sysctl.3: sys/types.h no longer needs to be explicitly included

Reviewed by:	imp
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D32562

lib/libc/gen/sysctl.3

@@ -28,7 +28,7 @@
 .\"	@(#)sysctl.3	8.4 (Berkeley) 5/9/95
 .\" $FreeBSD$
 .\"
-.Dd October 30, 2020
+.Dd October 18, 2021
 .Dt SYSCTL 3
 .Os
 .Sh NAME
@@ -39,7 +39,6 @@
 .Sh LIBRARY
 .Lb libc
 .Sh SYNOPSIS
-.In sys/types.h
 .In sys/sysctl.h
 .Ft int
 .Fn sysctl "const int *name" "u_int namelen" "void *oldp" "size_t *oldlenp" "const void *newp" "size_t newlen"