block: don't check ->rq_disk in merges

There is a 1:1 relationship between request_queues and gendisks now, so
no need for these extra checks.

Signed-off-by: Christoph Hellwig <[e-mail]>
Reviewed-by: Martin K. Petersen <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jens Axboe <[e-mail]>

block/blk-merge.c

···
 	if (req_op(req) != req_op(next))
 		return NULL;
 
-	if (rq_data_dir(req) != rq_data_dir(next)
-	    || req->rq_disk != next->rq_disk)
+	if (rq_data_dir(req) != rq_data_dir(next))
 		return NULL;
 
 	if (req_op(req) == REQ_OP_WRITE_SAME &&
···
 
 	/* different data direction or already started, don't merge */
 	if (bio_data_dir(bio) != rq_data_dir(rq))
-		return false;
-
-	/* must be same device */
-	if (rq->rq_disk != bio->bi_bdev->bd_disk)
 		return false;
 
 	/* only merge integrity protected bio into ditto rq */