man: Formatting fixes

Format 'errno' with .I. Format error constants in bold.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
diff --git a/man/keyctl_chown.3 b/man/keyctl_chown.3
index 902fb65..9806d93 100644
--- a/man/keyctl_chown.3
+++ b/man/keyctl_chown.3
@@ -46,7 +46,9 @@
 .B 0 .
 On error, the value
 .B -1
-will be returned and errno will have been set to an appropriate error.
+will be returned and
+.I errno
+will have been set to an appropriate error.
 .\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
 .SH ERRORS
 .TP
diff --git a/man/keyctl_clear.3 b/man/keyctl_clear.3
index be446a3..3d2ca96 100644
--- a/man/keyctl_clear.3
+++ b/man/keyctl_clear.3
@@ -34,7 +34,9 @@
 .BR 0 .
 On error, the value
 .B -1
-will be returned and errno will have been set to an appropriate error.
+will be returned and
+.I errno
+will have been set to an appropriate error.
 .\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
 .SH ERRORS
 .TP
diff --git a/man/keyctl_describe.3 b/man/keyctl_describe.3
index 904720a..49b0906 100644
--- a/man/keyctl_describe.3
+++ b/man/keyctl_describe.3
@@ -65,13 +65,17 @@
 small, then the size of buffer required will be returned, but no data will be
 transferred.  On error, the value
 .B -1
-will be returned and errno will have been set to an appropriate error.
+will be returned and
+.I errno
+will have been set to an appropriate error.
 .P
 On success
 .BR keyctl_describe_alloc ()
 returns the amount of data in the buffer, less the NUL terminator.  On error, the value
 .B -1
-will be returned and errno will have been set to an appropriate error.
+will be returned and
+.I errno
+will have been set to an appropriate error.
 .\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
 .SH ERRORS
 .TP
diff --git a/man/keyctl_get_keyring_ID.3 b/man/keyctl_get_keyring_ID.3
index 74d6f18..c19b3af 100644
--- a/man/keyctl_get_keyring_ID.3
+++ b/man/keyctl_get_keyring_ID.3
@@ -61,7 +61,9 @@
 .BR keyctl_get_keyring_ID ()
 returns the serial number of the key it found.  On error, the value
 .B -1
-will be returned and errno will have been set to an appropriate error.
+will be returned and
+.I errno
+will have been set to an appropriate error.
 .\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
 .SH ERRORS
 .TP
diff --git a/man/keyctl_get_persistent.3 b/man/keyctl_get_persistent.3
index 59077df..bc848a1 100644
--- a/man/keyctl_get_persistent.3
+++ b/man/keyctl_get_persistent.3
@@ -43,7 +43,7 @@
 is not
 .B -1
 then error
-.I EPERM
+.B EPERM
 will be given if the user ID requested does not match either the caller's real
 or effective user IDs or if the calling process does not have
 .B SetUid
@@ -57,7 +57,9 @@
 .BR keyctl_get_persistent ()
 returns the serial number of the persistent keyring.  On error, the value
 .B -1
-will be returned and errno will have been set to an appropriate error.
+will be returned and
+.I errno
+will have been set to an appropriate error.
 .\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
 .SH ERRORS
 .TP
diff --git a/man/keyctl_get_security.3 b/man/keyctl_get_security.3
index 49bda40..f15cb69 100644
--- a/man/keyctl_get_security.3
+++ b/man/keyctl_get_security.3
@@ -55,13 +55,17 @@
 small, then the size of buffer required will be returned, but no data will be
 transferred.  On error, the value
 .B -1
-will be returned and errno will have been set to an appropriate error.
+will be returned and
+.I errno
+will have been set to an appropriate error.
 .P
 On success
 .BR keyctl_get_security_alloc ()
 returns the amount of data in the buffer, less the NUL terminator.  On error, the value
 .B -1
-will be returned and errno will have been set to an appropriate error.
+will be returned and
+.I errno
+will have been set to an appropriate error.
 .\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
 .SH ERRORS
 .TP
diff --git a/man/keyctl_instantiate.3 b/man/keyctl_instantiate.3
index 18c371f..7989e22 100644
--- a/man/keyctl_instantiate.3
+++ b/man/keyctl_instantiate.3
@@ -104,7 +104,7 @@
 .I error
 specifies the error to be returned when a search hits the key (this is
 typically
-.IR EKEYREJECTED ", " EKEYREVOKED " or " EKEYEXPIRED ")."
+.BR EKEYREJECTED ", " EKEYREVOKED " or " EKEYEXPIRED ")."
 Note that keyctl_reject() falls back to keyctl_negate() if the kernel does not
 support it.
 .P
@@ -140,7 +140,9 @@
 .BR 0 .
 On error, the value
 .B -1
-will be returned and errno will have been set to an appropriate error.
+will be returned and
+.I errno
+will have been set to an appropriate error.
 .\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
 .SH ERRORS
 .TP
diff --git a/man/keyctl_invalidate.3 b/man/keyctl_invalidate.3
index 86abe48..3d2bb9f 100644
--- a/man/keyctl_invalidate.3
+++ b/man/keyctl_invalidate.3
@@ -37,7 +37,9 @@
 .BR 0 .
 On error, the value
 .B -1
-will be returned and errno will have been set to an appropriate error.
+will be returned and
+.I errno
+will have been set to an appropriate error.
 .\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
 .SH ERRORS
 .TP
diff --git a/man/keyctl_join_session_keyring.3 b/man/keyctl_join_session_keyring.3
index 2071fbd..3361622 100644
--- a/man/keyctl_join_session_keyring.3
+++ b/man/keyctl_join_session_keyring.3
@@ -45,7 +45,9 @@
 .BR keyctl_join_session_keyring ()
 returns the serial number of the key it found or created.  On error, the value
 .B -1
-will be returned and errno will have been set to an appropriate error.
+will be returned and
+.I errno
+will have been set to an appropriate error.
 .\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
 .SH ERRORS
 .TP
diff --git a/man/keyctl_link.3 b/man/keyctl_link.3
index c73c4ef..1e95c1f 100644
--- a/man/keyctl_link.3
+++ b/man/keyctl_link.3
@@ -54,7 +54,9 @@
 .BR 0 .
 On error, the value
 .B -1
-will be returned and errno will have been set to an appropriate error.
+will be returned and
+.I errno
+will have been set to an appropriate error.
 .\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
 .SH ERRORS
 .TP
diff --git a/man/keyctl_read.3 b/man/keyctl_read.3
index fa9485f..a5eb650 100644
--- a/man/keyctl_read.3
+++ b/man/keyctl_read.3
@@ -69,7 +69,9 @@
 .BR keyctl_read_alloc ()
 returns the amount of data in the buffer.
 .P
-On error, both functions set errno to an appropriate code and return the value
+On error, both functions set
+.I errno
+to an appropriate code and return the value
 .BR -1 .
 .\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
 .SH ERRORS
diff --git a/man/keyctl_revoke.3 b/man/keyctl_revoke.3
index 1551849..2300958 100644
--- a/man/keyctl_revoke.3
+++ b/man/keyctl_revoke.3
@@ -37,7 +37,9 @@
 .BR 0 .
 On error, the value
 .B -1
-will be returned and errno will have been set to an appropriate error.
+will be returned and
+.I errno
+will have been set to an appropriate error.
 .\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
 .SH ERRORS
 .TP
diff --git a/man/keyctl_search.3 b/man/keyctl_search.3
index fb44c25..dba012f 100644
--- a/man/keyctl_search.3
+++ b/man/keyctl_search.3
@@ -82,7 +82,9 @@
 .BR keyctl_search ()
 returns the serial number of the key it found.  On error, the value
 .B -1
-will be returned and errno will have been set to an appropriate error.
+will be returned and
+.I errno
+will have been set to an appropriate error.
 .\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
 .SH ERRORS
 .TP
diff --git a/man/keyctl_session_to_parent.3 b/man/keyctl_session_to_parent.3
index 5b15ae5..af77e53 100644
--- a/man/keyctl_session_to_parent.3
+++ b/man/keyctl_session_to_parent.3
@@ -39,7 +39,9 @@
 .BR keyctl_session_to_parent ()
 returns 0.  On error, the value
 .B -1
-will be returned and errno will have been set to an appropriate error.
+will be returned and
+.I errno
+will have been set to an appropriate error.
 .\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
 .SH ERRORS
 .TP
diff --git a/man/keyctl_set_reqkey_keyring.3 b/man/keyctl_set_reqkey_keyring.3
index c5f41e9..a83976e 100644
--- a/man/keyctl_set_reqkey_keyring.3
+++ b/man/keyctl_set_reqkey_keyring.3
@@ -68,7 +68,9 @@
 .BR 0 .
 On error, the value
 .B -1
-will be returned and errno will have been set to an appropriate error.
+will be returned and
+.I errno
+will have been set to an appropriate error.
 .\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
 .SH ERRORS
 .TP
diff --git a/man/keyctl_set_timeout.3 b/man/keyctl_set_timeout.3
index 91cc92f..e91b405 100644
--- a/man/keyctl_set_timeout.3
+++ b/man/keyctl_set_timeout.3
@@ -42,7 +42,9 @@
 .B 0 .
 On error, the value
 .B -1
-will be returned and errno will have been set to an appropriate error.
+will be returned and
+.I errno
+will have been set to an appropriate error.
 .\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
 .SH ERRORS
 .TP
diff --git a/man/keyctl_setperm.3 b/man/keyctl_setperm.3
index 3bb9707..9c4aca5 100644
--- a/man/keyctl_setperm.3
+++ b/man/keyctl_setperm.3
@@ -91,7 +91,9 @@
 .B 0 .
 On error, the value
 .B -1
-will be returned and errno will have been set to an appropriate error.
+will be returned and
+.I errno
+will have been set to an appropriate error.
 .\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
 .SH ERRORS
 .TP
diff --git a/man/keyctl_update.3 b/man/keyctl_update.3
index d9575de..538cd38 100644
--- a/man/keyctl_update.3
+++ b/man/keyctl_update.3
@@ -44,7 +44,9 @@
 .BR 0 .
 On error, the value
 .B -1
-will be returned and errno will have been set to an appropriate error.
+will be returned and
+.I errno
+will have been set to an appropriate error.
 .\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
 .SH ERRORS
 .TP
diff --git a/man/recursive_key_scan.3 b/man/recursive_key_scan.3
index 7d69d5d..ed7f440 100644
--- a/man/recursive_key_scan.3
+++ b/man/recursive_key_scan.3
@@ -64,7 +64,9 @@
 A pointer to the raw description and its length as retrieved with
 .IR keyctl_describe_alloc ().
 These will be NULL and \-1 respectively if the description couldn't be
-retrieved and errno will retain the error from
+retrieved and
+.I errno
+will retain the error from
 .IR keyctl_describe_alloc ().
 .TP
 .B data