block/bfq: fix ifdef for CONFIG_BFQ_GROUP_IOSCHED=y

Replace BFQ_GROUP_IOSCHED_ENABLED with CONFIG_BFQ_GROUP_IOSCHED.
Code under these ifdefs never worked, something might be broken.

Fixes: 0471559c ("block, bfq: add/remove entity weights correctly")
Fixes: 73d58118 ("block, bfq: consider also ioprio classes in symmetry detection")
Reviewed-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/bfq-iosched.c

@@ -674,7 +674,7 @@ static bool bfq_symmetric_scenario(struct bfq_data *bfqd)
 	 * at least two nodes.
 	 */
 	return !(varied_queue_weights || multiple_classes_busy
-#ifdef BFQ_GROUP_IOSCHED_ENABLED
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
 	       || bfqd->num_groups_with_pending_reqs > 0
 #endif
 		);

block/bfq-wf2q.c

@@ -1012,7 +1012,7 @@ static void __bfq_activate_entity(struct bfq_entity *entity,
 		entity->on_st = true;
 	}
 
-#ifdef BFQ_GROUP_IOSCHED_ENABLED
+#ifdef CONFIG_BFQ_GROUP_IOSCHED
 	if (!bfq_entity_to_bfqq(entity)) { /* bfq_group */
 		struct bfq_group *bfqg =
 			container_of(entity, struct bfq_group, entity);