btrfs_lookup_dir_item() can return either ERR_PTRs or null.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
        dir_id = btrfs_super_root_dir(&root->fs_info->super_copy);
        di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
                                   dir_id, "default", 7, 1);
-       if (!di) {
+       if (IS_ERR_OR_NULL(di)) {
                btrfs_free_path(path);
                btrfs_end_transaction(trans, root);
                printk(KERN_ERR "Umm, you don't have the default dir item, "