btrfs: use btrfs_for_each_slot in btrfs_search_dir_index_item

This function can be simplified by refactoring to use the new iterator
macro.  No functional changes.

Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Signed-off-by: Gabriel Niebler <gniebler@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/dir-item.c

@@ -325,47 +325,28 @@ btrfs_search_dir_index_item(struct btrfs_root *root,
 			    struct btrfs_path *path, u64 dirid,
 			    const char *name, int name_len)
 {
-	struct extent_buffer *leaf;
 	struct btrfs_dir_item *di;
 	struct btrfs_key key;
-	u32 nritems;
 	int ret;
 
 	key.objectid = dirid;
 	key.type = BTRFS_DIR_INDEX_KEY;
 	key.offset = 0;
 
-	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
-	if (ret < 0)
-		return ERR_PTR(ret);
-
-	leaf = path->nodes[0];
-	nritems = btrfs_header_nritems(leaf);
-
-	while (1) {
-		if (path->slots[0] >= nritems) {
-			ret = btrfs_next_leaf(root, path);
-			if (ret < 0)
-				return ERR_PTR(ret);
-			if (ret > 0)
-				break;
-			leaf = path->nodes[0];
-			nritems = btrfs_header_nritems(leaf);
-			continue;
-		}
-
-		btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+	btrfs_for_each_slot(root, &key, &key, path, ret) {
 		if (key.objectid != dirid || key.type != BTRFS_DIR_INDEX_KEY)
 			break;
 
 		di = btrfs_match_dir_item_name(root->fs_info, path,
 					       name, name_len);
 		if (di)
 			return di;
-
-		path->slots[0]++;
 	}
-	return NULL;
+	/* Adjust return code if the key was not found in the next leaf. */
+	if (ret > 0)
+		ret = 0;
+
+	return ERR_PTR(ret);
 }
 
 struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,