btrfs: use btrfs_path auto free in zoned.c

All cleanup paths lead to btrfs_path_free so path can be defined with
the automatic freeing callback in the following functions:

- calculate_emulated_zone_size()
- calculate_alloc_pointer()

Signed-off-by: Leo Martins <loemra.dev@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/zoned.c

@@ -287,7 +287,7 @@ static int btrfs_get_dev_zones(struct btrfs_device *device, u64 pos,
 /* The emulated zone size is determined from the size of device extent */
 static int calculate_emulated_zone_size(struct btrfs_fs_info *fs_info)
 {
-	struct btrfs_path *path;
+	BTRFS_PATH_AUTO_FREE(path);
 	struct btrfs_root *root = fs_info->dev_root;
 	struct btrfs_key key;
 	struct extent_buffer *leaf;
@@ -304,28 +304,21 @@ static int calculate_emulated_zone_size(struct btrfs_fs_info *fs_info)
 
 	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 	if (ret < 0)
-		goto out;
+		return ret;
 
 	if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
 		ret = btrfs_next_leaf(root, path);
 		if (ret < 0)
-			goto out;
+			return ret;
 		/* No dev extents at all? Not good */
-		if (ret > 0) {
-			ret = -EUCLEAN;
-			goto out;
-		}
+		if (ret > 0)
+			return -EUCLEAN;
 	}
 
 	leaf = path->nodes[0];
 	dext = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_extent);
 	fs_info->zone_size = btrfs_dev_extent_length(leaf, dext);
-	ret = 0;
-
-out:
-	btrfs_free_path(path);
-
-	return ret;
+	return 0;
 }
 
 int btrfs_get_dev_zone_info_all_devices(struct btrfs_fs_info *fs_info)
@@ -1211,7 +1204,7 @@ static int calculate_alloc_pointer(struct btrfs_block_group *cache,
 {
 	struct btrfs_fs_info *fs_info = cache->fs_info;
 	struct btrfs_root *root;
-	struct btrfs_path *path;
+	BTRFS_PATH_AUTO_FREE(path);
 	struct btrfs_key key;
 	struct btrfs_key found_key;
 	int ret;
@@ -1246,15 +1239,15 @@ static int calculate_alloc_pointer(struct btrfs_block_group *cache,
 	if (!ret)
 		ret = -EUCLEAN;
 	if (ret < 0)
-		goto out;
+		return ret;
 
 	ret = btrfs_previous_extent_item(root, path, cache->start);
 	if (ret) {
 		if (ret == 1) {
 			ret = 0;
 			*offset_ret = 0;
 		}
-		goto out;
+		return ret;
 	}
 
 	btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
@@ -1266,15 +1259,10 @@ static int calculate_alloc_pointer(struct btrfs_block_group *cache,
 
 	if (!(found_key.objectid >= cache->start &&
 	       found_key.objectid + length <= cache->start + cache->length)) {
-		ret = -EUCLEAN;
-		goto out;
+		return -EUCLEAN;
 	}
 	*offset_ret = found_key.objectid + length - cache->start;
-	ret = 0;
-
-out:
-	btrfs_free_path(path);
-	return ret;
+	return 0;
 }
 
 struct zone_info {