mm/vmscan.c: remove unused return value of shrink_node

The return value of shrink_node is not used, so remove unnecessary
operations.

Link: http://lkml.kernel.org/r/20191128143524.3223-1-fishland@aliyun.comSigned-off-by: NLiu Song <liu.song11@zte.com.cn>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mm/vmscan.c

@@ -2695,7 +2695,7 @@ static void shrink_node_memcgs(pg_data_t *pgdat, struct scan_control *sc)
 	} while ((memcg = mem_cgroup_iter(target_memcg, memcg, NULL)));
 }
 
-static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc)
+static void shrink_node(pg_data_t *pgdat, struct scan_control *sc)
 {
 	struct reclaim_state *reclaim_state = current->reclaim_state;
 	unsigned long nr_reclaimed, nr_scanned;
@@ -2874,8 +2874,6 @@ static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc)
 	 */
 	if (reclaimable)
 		pgdat->kswapd_failures = 0;
-
-	return reclaimable;
 }
 
 /*