block: remove the declaration of elevator_init_mq function

In commit 1e44bed ("block: unifying elevator change"), the
elevator_init_mq function was deleted, but its declaration in elevator.h
was overlooked. This patch fixes it.

Signed-off-by: Chengkaitao <chengkaitao@kylinos.cn>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: Chengkaitao

block/elevator.h

@@ -171,7 +171,6 @@ extern bool elv_attempt_insert_merge(struct request_queue *, struct request *,
 				     struct list_head *);
 extern struct request *elv_former_request(struct request_queue *, struct request *);
 extern struct request *elv_latter_request(struct request_queue *, struct request *);
-void elevator_init_mq(struct request_queue *q);
 
 /*
  * io scheduler registration