mq-deadline: Enable auto-loading when built as module

The block core requests modules with the "-iosched" name suffix, but
mq-deadline does not have that suffix.  Add an alias.

Fixes: 945ffb60c1 ("mq-deadline: add blk-mq adaptation of the deadline ...")
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/mq-deadline.c

@@ -659,6 +659,7 @@ static struct elevator_type mq_deadline = {
 	.elevator_name = "mq-deadline",
 	.elevator_owner = THIS_MODULE,
 };
+MODULE_ALIAS("mq-deadline-iosched");
 
 static int __init deadline_init(void)
 {