mm: memcontrol: correct the comment of mem_cgroup_iter()

Since commit bbec2e1517 ("mm: rename page_counter's count/limit into
usage/max"), the arg @reclaim has no priority field anymore.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Link: https://lkml.kernel.org/r/20200913094129.44558-1-linmiaohe@huawei.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memcontrol.c

@@ -1102,9 +1102,9 @@ static __always_inline struct mem_cgroup *get_mem_cgroup_from_current(void)
  * invocations for reference counting, or use mem_cgroup_iter_break()
  * to cancel a hierarchy walk before the round-trip is complete.
  *
- * Reclaimers can specify a node and a priority level in @reclaim to
- * divide up the memcgs in the hierarchy among all concurrent
- * reclaimers operating on the same node and priority.
+ * Reclaimers can specify a node in @reclaim to divide up the memcgs
+ * in the hierarchy among all concurrent reclaimers operating on the
+ * same node.
  */
 struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
 				   struct mem_cgroup *prev,