Bug 32793

	The sysctl.3 man page describes sysctl() returning EOPNOTSUPP
	in the case the named variable is not found. This is obviously wrong
	because sysctl() returns ENOENT. There is only one instance of
	EOPNOTSUPP in kern_sysctl.c and this is for the BSDI 1.0 getkerninfo.

Fix: Patch for /usr/src/lib/libc/gen/sysctl.3:
How-To-Repeat: 	Compile and run the following test program which tries to access an
	non-existing variable. See it printing an errno of 2 (ENOENT).

#include <sys/types.h>
#include <sys/sysctl.h>
#include <sys/socket.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <net/if.h>
#include <net/if_mib.h>

int
main(int argc, char *argv[])
{
	u_int ifnum;
	int name[6];
	size_t len = sizeof(ifnum);

	name[0] = CTL_NET;
	name[1] = PF_LINK;
	name[2] = NETLINK_GENERIC;
	name[3] = IFMIB_SYSTEM;
	name[4] = 17;

	if (sysctl(name, 5, &ifnum, &len, NULL, 0) == -1)
		err(1, "sysctl %d", errno);

	return (0);
}