blk-mq: split the plug and sync cases in blk_mq_make_request

		list_add_tail(&rq->queuelist, &plug->mq_list);

		goto done;

	} else if (((plug && !blk_queue_nomerges(q)) || is_sync)) {

		struct request *old_rq = NULL;

	} else if (plug && !blk_queue_nomerges(q)) {

		blk_mq_bio_to_request(rq, bio);

		/*

		 * We do limited plugging. If the bio can be merged, do that.

		 * Otherwise the existing request in the plug list will be

		 * issued. So the plug list will have one request at most

		 * The plug list might get flushed before this. If that happens,

		 * the plug list is empty, and same_queue_rq is invalid.

		 */

		if (plug) {

			/*

			 * The plug list might get flushed before this. If that

			 * happens, same_queue_rq is invalid and plug list is

			 * empty

			 */

			if (same_queue_rq && !list_empty(&plug->mq_list)) {

				old_rq = same_queue_rq;

				list_del_init(&old_rq->queuelist);

			}

		if (list_empty(&plug->mq_list))

			same_queue_rq = NULL;

		if (same_queue_rq)

			list_del_init(&same_queue_rq->queuelist);

		list_add_tail(&rq->queuelist, &plug->mq_list);

		} else /* is_sync */

			old_rq = rq;

		blk_mq_put_ctx(data.ctx);

		if (same_queue_rq)

			blk_mq_try_issue_directly(data.hctx, same_queue_rq,

					&cookie);

		goto done;

	} else if (is_sync) {

		blk_mq_bio_to_request(rq, bio);

		blk_mq_put_ctx(data.ctx);

		if (old_rq)

			blk_mq_try_issue_directly(data.hctx, old_rq, &cookie);

		blk_mq_try_issue_directly(data.hctx, rq, &cookie);

		goto done;

	}