block: Minor blk_account_io_start usage cleanup

blk_account_io_start does not need to be wrapped with blk_do_io_stat
ais it already checks for that condition.
Signed-off-by: Michael Callahan <michaelcallahan@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

block/blk-mq.c

@@ -1122,8 +1122,7 @@ static void blk_mq_bio_to_request(struct request *rq, struct bio *bio)
 {
 	init_request_from_bio(rq, bio);
 
-	if (blk_do_io_stat(rq))
-		blk_account_io_start(rq, 1);
+	blk_account_io_start(rq, 1);
 }
 
 static inline bool hctx_allow_merges(struct blk_mq_hw_ctx *hctx)