man: Consistently format pathnames as italic

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
diff --git a/man/find_key_by_type_and_name.3 b/man/find_key_by_type_and_name.3
index 301792e..88c9880 100644
--- a/man/find_key_by_type_and_name.3
+++ b/man/find_key_by_type_and_name.3
@@ -26,7 +26,8 @@
 and exact
 .IR description ,
 firstly in the thread, process and session keyrings to which a process is
-subscribed and secondly in /proc/keys.
+subscribed and secondly in
+.IR /proc/keys .
 .P
 If a key is found, and
 .I destringid
diff --git a/man/keyctl.1 b/man/keyctl.1
index 1533b73..859e340 100644
--- a/man/keyctl.1
+++ b/man/keyctl.1
@@ -145,12 +145,13 @@
 (*) Keyring by name: \fB%:<name>\fR
 .P
 A named keyring.  This will be searched for in the process's keyrings and in
-/proc/keys.
+.IR /proc/keys .
 .P
 (*) Key by name: \fB%<type>:<name>\fR
 .P
 A named key of the given type.  This will be searched for in the process's
-keyrings and in /proc/keys.
+keyrings and in
+.IR /proc/keys .
 .SH COMMAND SYNTAX
 Any non-ambiguous shortening of a command name may be used in lieu of the full
 command name. This facility should not be used in scripting as new commands may
@@ -217,7 +218,9 @@
 .P
 If there is no key, the first command will simply return the error ENOKEY and
 fail. The second and third commands will create a partial key with the type and
-description, and call out to \fB/sbin/request-key\fR with that key and the
+description, and call out to
+.IR /sbin/request-key
+with that key and the
 extra information supplied. This will then attempt to instantiate the key in
 some manner, such that a valid key is obtained.
 .P
@@ -590,7 +593,9 @@
 \fBkeyctl reject\fR <key> <timeout> <error> <keyring>
 .P
 These commands are used to attach data to a partially set up key (as created by
-the kernel and passed to /sbin/request-key).  "instantiate" marks a key as
+the kernel and passed to
+.IR /sbin/request-key ).
+"instantiate" marks a key as
 being valid and attaches the data as the payload.  "negate" and "reject" mark a
 key as invalid and sets a timeout on it so that it'll go away after a while.
 This prevents a lot of quickly sequential requests from slowing the system down
diff --git a/man/keyutils.7 b/man/keyutils.7
index bd1cd2f..a388acf 100644
--- a/man/keyutils.7
+++ b/man/keyutils.7
@@ -80,9 +80,9 @@
 program.  What this does with any particular key is configurable in:
 .P
 .RS
-.B /etc/request-key.conf
+.I /etc/request-key.conf
 .br
-.B /etc/request-key.d/
+.I /etc/request-key.d/
 .RE
 .P
 See the