block: get rid of MQ scheduler ops union

This is a remnant of when we had ops for both SQ and MQ
schedulers. Now it's just MQ, so get rid of the union.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 44c7e56..c7636cb 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -5724,7 +5724,7 @@ static struct elv_fs_entry bfq_attrs[] = {
 };
 
 static struct elevator_type iosched_bfq_mq = {
-	.ops.mq = {
+	.ops = {
 		.limit_depth		= bfq_limit_depth,
 		.prepare_request	= bfq_prepare_request,
 		.requeue_request        = bfq_finish_requeue_request,