FreeBSD: fix build without kernel option MAC

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Mark Johnston <markj@FreeBSD.org>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Gleb Smirnoff <glebius@FreeBSD.org>
Closes #16446

module/os/freebsd/zfs/zfs_vnops_os.c

@@ -6125,7 +6125,9 @@ zfs_freebsd_copy_file_range(struct vop_copy_file_range_args *ap)
 	    error == EOPNOTSUPP)
 		goto bad_locked_fallback;
 	*ap->a_lenp = (size_t)len;
+#ifdef MAC
 out_locked:
+#endif
 	if (invp != outvp)
 		VOP_UNLOCK(invp);
 	VOP_UNLOCK(outvp);