mm/vmscan.c: don't disable irq again when count pgrefill for memcg

We can use __count_memcg_events() directly because this callsite is alreay
protected by spin_lock_irq().

Link: http://lkml.kernel.org/r/1556093494-30798-1-git-send-email-laoar.shao@gmail.com
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Author: laoar

mm/vmscan.c

@@ -2022,7 +2022,7 @@ static void shrink_active_list(unsigned long nr_to_scan,
 	reclaim_stat->recent_scanned[file] += nr_taken;
 
 	__count_vm_events(PGREFILL, nr_scanned);
-	count_memcg_events(lruvec_memcg(lruvec), PGREFILL, nr_scanned);
+	__count_memcg_events(lruvec_memcg(lruvec), PGREFILL, nr_scanned);
 
 	spin_unlock_irq(&pgdat->lru_lock);