mm: workingset: use cheaper __inc_lruvec_state in irqsafe node reclaim

No need to use the preemption-safe lruvec state function inside the
reclaim region that has irqs disabled.

Link: http://lkml.kernel.org/r/20181009184732.762-3-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Rik van Riel <riel@surriel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/workingset.c

@@ -500,7 +500,7 @@ static enum lru_status shadow_lru_isolate(struct list_head *item,
 	}
 	if (WARN_ON_ONCE(node->exceptional))
 		goto out_invalid;
-	inc_lruvec_page_state(virt_to_page(node), WORKINGSET_NODERECLAIM);
+	__inc_lruvec_page_state(virt_to_page(node), WORKINGSET_NODERECLAIM);
 	__radix_tree_delete_node(&mapping->i_pages, node,
 				 workingset_lookup_update(mapping));