btrfs: remove root parameter from transaction commit/end routines

Now we only use the root parameter to print the root objectid in
a tracepoint.  We can use the root parameter from the transaction
handle for that.  It's also used to join the transaction with
async commits, so we remove the comment that it's just for checking.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 135bb79..3e473e9 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -2576,9 +2576,9 @@ static void btrfs_qgroup_rescan_worker(struct btrfs_work *work)
 			err = qgroup_rescan_leaf(fs_info, path, trans);
 		}
 		if (err > 0)
-			btrfs_commit_transaction(trans, fs_info->fs_root);
+			btrfs_commit_transaction(trans);
 		else
-			btrfs_end_transaction(trans, fs_info->fs_root);
+			btrfs_end_transaction(trans);
 	}
 
 out:
@@ -2613,7 +2613,7 @@ static void btrfs_qgroup_rescan_worker(struct btrfs_work *work)
 		err = ret;
 		btrfs_err(fs_info, "fail to update qgroup status: %d", err);
 	}
-	btrfs_end_transaction(trans, fs_info->quota_root);
+	btrfs_end_transaction(trans);
 
 	if (btrfs_fs_closing(fs_info)) {
 		btrfs_info(fs_info, "qgroup scan paused");
@@ -2732,7 +2732,7 @@ btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info)
 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
 		return PTR_ERR(trans);
 	}
-	ret = btrfs_commit_transaction(trans, fs_info->fs_root);
+	ret = btrfs_commit_transaction(trans);
 	if (ret) {
 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
 		return ret;