Btrfs: remove residual code in delayed inode async helper

	trans->block_rsv = &root->fs_info->delayed_block_rsv;

	__btrfs_commit_inode_delayed_items(trans, path, delayed_node);

	/*

	 * Maybe new delayed items have been inserted, so we need requeue

	 * the work. Besides that, we must dequeue the empty delayed nodes

	 * to avoid the race between delayed items balance and the worker.

	 * The race like this:

	 * 	Task1				Worker thread

	 * 					count == 0, needn't requeue

	 * 					  also needn't insert the

	 * 					  delayed node into prepare

	 * 					  list again.

	 * 	add lots of delayed items

	 * 	queue the delayed node

	 * 	  already in the list,

	 * 	  and not in the prepare

	 * 	  list, it means the delayed

	 * 	  node is being dealt with

	 * 	  by the worker.

	 * 	do delayed items balance

	 * 	  the delayed node is being

	 * 	  dealt with by the worker

	 * 	  now, just wait.

	 * 	  				the worker goto idle.

	 * Task1 will sleep until the transaction is commited.

	 */

	mutex_lock(&delayed_node->mutex);

	btrfs_dequeue_delayed_node(root->fs_info->delayed_root, delayed_node);

	mutex_unlock(&delayed_node->mutex);

	trans->block_rsv = block_rsv;

	btrfs_end_transaction_dmeta(trans, root);