btrfs: drop unused parameter from btrfs_release_path

parameter tree root it's not used since commit
5f39d397dfbe140a14edecd4e73c34ce23c4f9ee ("Btrfs: Create extent_buffer
interface for large blocksizes")

Signed-off-by: David Sterba <dsterba@suse.cz>
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index d06abe2..48fafcb 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -61,7 +61,7 @@
 	if (ret < 0)
 		return ERR_PTR(ret);
 	if (ret > 0) {
-		btrfs_release_path(root, path);
+		btrfs_release_path(path);
 		return ERR_PTR(-ENOENT);
 	}
 
@@ -70,7 +70,7 @@
 				struct btrfs_free_space_header);
 	btrfs_free_space_key(leaf, header, &disk_key);
 	btrfs_disk_key_to_cpu(&location, &disk_key);
-	btrfs_release_path(root, path);
+	btrfs_release_path(path);
 
 	inode = btrfs_iget(root->fs_info->sb, &location, root, NULL);
 	if (!inode)
@@ -134,7 +134,7 @@
 	btrfs_set_inode_block_group(leaf, inode_item,
 				    block_group->key.objectid);
 	btrfs_mark_buffer_dirty(leaf);
-	btrfs_release_path(root, path);
+	btrfs_release_path(path);
 
 	key.objectid = BTRFS_FREE_SPACE_OBJECTID;
 	key.offset = block_group->key.objectid;
@@ -143,7 +143,7 @@
 	ret = btrfs_insert_empty_item(trans, root, path, &key,
 				      sizeof(struct btrfs_free_space_header));
 	if (ret < 0) {
-		btrfs_release_path(root, path);
+		btrfs_release_path(path);
 		return ret;
 	}
 	leaf = path->nodes[0];
@@ -152,7 +152,7 @@
 	memset_extent_buffer(leaf, 0, (unsigned long)header, sizeof(*header));
 	btrfs_set_free_space_key(leaf, header, &disk_key);
 	btrfs_mark_buffer_dirty(leaf);
-	btrfs_release_path(root, path);
+	btrfs_release_path(path);
 
 	return 0;
 }
@@ -822,7 +822,7 @@
 					 EXTENT_DIRTY | EXTENT_DELALLOC |
 					 EXTENT_DO_ACCOUNTING, 0, 0, NULL,
 					 GFP_NOFS);
-			btrfs_release_path(root, path);
+			btrfs_release_path(path);
 			goto out_free;
 		}
 	}
@@ -832,7 +832,7 @@
 	btrfs_set_free_space_bitmaps(leaf, header, bitmaps);
 	btrfs_set_free_space_generation(leaf, header, trans->transid);
 	btrfs_mark_buffer_dirty(leaf);
-	btrfs_release_path(root, path);
+	btrfs_release_path(path);
 
 	ret = 1;