blk-cgroup: don't use removal safe list iterators

Commit f1c006f moved deletion of the list blkg->q_node from
blkg_destroy() to blkg_free_workfn(). Switch to using the list
iterators, as we don't need removal protection anymore.

Signed-off-by: Daniel Vacek <[email protected]>
Acked-by: Tejun Heo <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

Author: Daniel Vacek

block/blk-cgroup.c

@@ -575,13 +575,13 @@ static void blkg_destroy(struct blkcg_gq *blkg)
 static void blkg_destroy_all(struct gendisk *disk)
 {
 	struct request_queue *q = disk->queue;
-	struct blkcg_gq *blkg, *n;
+	struct blkcg_gq *blkg;
 	int count = BLKG_DESTROY_BATCH_SIZE;
 	int i;
 
 restart:
 	spin_lock_irq(&q->queue_lock);
-	list_for_each_entry_safe(blkg, n, &q->blkg_list, q_node) {
+	list_for_each_entry(blkg, &q->blkg_list, q_node) {
 		struct blkcg *blkcg = blkg->blkcg;
 
 		if (hlist_unhashed(&blkg->blkcg_node))