[PATCH] Remove queue merging hooks

We have full flexibility of merging parameters now, so we can remove the
hooks that define back/front/request merge strategies. Nobody is using
them anymore.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 41a2ea3..f02f48a 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -265,7 +265,7 @@
 
 	if (!rq->bio)
 		blk_rq_bio_prep(q, rq, bio);
-	else if (!q->back_merge_fn(q, rq, bio))
+	else if (!ll_back_merge_fn(q, rq, bio))
 		return -EINVAL;
 	else {
 		rq->biotail->bi_next = bio;