block: remove unused variable in bio_attempt_front_merge()

sector is never read inside the function.
Signed-off-by: Luca Tettamanti <kronos.it@gmail.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

block/blk-core.c

@@ -1130,7 +1130,6 @@ static bool bio_attempt_front_merge(struct request_queue *q,
 				    struct request *req, struct bio *bio)
 {
 	const int ff = bio->bi_rw & REQ_FAILFAST_MASK;
-	sector_t sector;
 
 	if (!ll_front_merge_fn(q, req, bio))
 		return false;
@@ -1140,8 +1139,6 @@ static bool bio_attempt_front_merge(struct request_queue *q,
 	if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff)
 		blk_rq_set_mixed_merge(req);
 
-	sector = bio->bi_sector;
-
 	bio->bi_next = req->bio;
 	req->bio = bio;