blk-mq: abstract out queue map

This is in preparation for allowing multiple sets of maps per
queue, if so desired.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 651be30..ed81b8e 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1812,7 +1812,7 @@ static int scsi_map_queues(struct blk_mq_tag_set *set)
 
 	if (shost->hostt->map_queues)
 		return shost->hostt->map_queues(shost);
-	return blk_mq_map_queues(set);
+	return blk_mq_map_queues(&set->map[0]);
 }
 
 void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q)