shmop.2: Remove unused include

Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
diff --git a/man2/shmop.2 b/man2/shmop.2
index c7e66af..52baed9 100644
--- a/man2/shmop.2
+++ b/man2/shmop.2
@@ -42,7 +42,6 @@
 shmat, shmdt \- System V shared memory operations
 .SH SYNOPSIS
 .nf
-.B #include <sys/types.h>
 .B #include <sys/shm.h>
 .PP
 .BI "void *shmat(int " shmid ", const void *" shmaddr ", int " shmflg );