xfs: fix ->mknod() return value on xfs_get_acl() failure

->mknod() should return negative on errors and PTR_ERR() gives
already negative value...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>

fs/xfs/linux-2.6/xfs_iops.c

@@ -182,7 +182,7 @@ xfs_vn_mknod(
 	if (IS_POSIXACL(dir)) {
 		default_acl = xfs_get_acl(dir, ACL_TYPE_DEFAULT);
 		if (IS_ERR(default_acl))
-			return -PTR_ERR(default_acl);
+			return PTR_ERR(default_acl);
 
 		if (!default_acl)
 			mode &= ~current_umask();