GFS2: gfs2_set_acl(): Cache "no acl" as well

When removing a default acl or setting an access acl that is entirely
represented in the file mode, we end up with acl == NULL in gfs2_set_acl(). In
that case, bring gfs2 in line with other file systems and cache the NULL acl
with set_cached_acl() instead of invalidating the cache with
forget_cached_acl().
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>

fs/gfs2/acl.c

@@ -110,11 +110,7 @@ int gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 	error = __gfs2_xattr_set(inode, name, data, len, 0, GFS2_EATYPE_SYS);
 	if (error)
 		goto out;
-
-	if (acl)
 	set_cached_acl(inode, type, acl);
-	else
-		forget_cached_acl(inode, type);
 out:
 	kfree(data);
 	return error;