blk-mq: remove a pointless queue enter pair in blk_mq_alloc_request

No need for two queue references.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-mq.c

@@ -406,10 +406,7 @@ struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op,
 	if (ret)
 		return ERR_PTR(ret);
 
-	blk_queue_enter_live(q);
 	rq = blk_mq_get_request(q, NULL, &alloc_data);
-	blk_queue_exit(q);
-
 	if (!rq)
 		goto out_queue_exit;
 	rq->__data_len = 0;