btrfs: move transaction abort to the error site btrfs_rebuild_free_space_tree()

The recommended pattern for transaction abort after error is to place it
right after the error is handled. That way it's easier to locate where
it failed and help debugging.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/free-space-tree.c

@@ -1328,8 +1328,11 @@ int btrfs_rebuild_free_space_tree(struct btrfs_fs_info *fs_info)
 	set_bit(BTRFS_FS_FREE_SPACE_TREE_UNTRUSTED, &fs_info->flags);
 
 	ret = clear_free_space_tree(trans, free_space_root);
-	if (ret)
-		goto abort;
+	if (ret) {
+		btrfs_abort_transaction(trans, ret);
+		btrfs_end_transaction(trans);
+		return ret;
+	}
 
 	node = rb_first_cached(&fs_info->block_group_cache_tree);
 	while (node) {
@@ -1338,8 +1341,11 @@ int btrfs_rebuild_free_space_tree(struct btrfs_fs_info *fs_info)
 		block_group = rb_entry(node, struct btrfs_block_group,
 				       cache_node);
 		ret = populate_free_space_tree(trans, block_group);
-		if (ret)
-			goto abort;
+		if (ret) {
+			btrfs_abort_transaction(trans, ret);
+			btrfs_end_transaction(trans);
+			return ret;
+		}
 		node = rb_next(node);
 	}
 
@@ -1350,10 +1356,6 @@ int btrfs_rebuild_free_space_tree(struct btrfs_fs_info *fs_info)
 	ret = btrfs_commit_transaction(trans);
 	clear_bit(BTRFS_FS_FREE_SPACE_TREE_UNTRUSTED, &fs_info->flags);
 	return ret;
-abort:
-	btrfs_abort_transaction(trans, ret);
-	btrfs_end_transaction(trans);
-	return ret;
 }
 
 static int __add_block_group_free_space(struct btrfs_trans_handle *trans,