[PATCH] mm/vmscan.c:Fix -Wunused-but-set-variable warning

[Kai Song]

We fix the following warning when building kernel with W=1:
mm/vmscan.c:1362:6: warning: variable 'err' set but not used [-Wunused-but-set-variable]

Signed-off-by: Kai Song <songkai01@xxxxxxxxxx>
---
 mm/vmscan.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index f8b43f131673..7cf702bc1959 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1359,7 +1359,6 @@ static unsigned int demote_page_list(struct list_head *demote_pages,
 {
 	int target_nid = next_demotion_node(pgdat->node_id);
 	unsigned int nr_succeeded;
-	int err;
 
 	if (list_empty(demote_pages))
 		return 0;
@@ -1368,7 +1367,7 @@ static unsigned int demote_page_list(struct list_head *demote_pages,
 		return 0;
 
 	/* Demotion ignores all cpuset and mempolicy settings */
-	err = migrate_pages(demote_pages, alloc_demote_page, NULL,
+	migrate_pages(demote_pages, alloc_demote_page, NULL,
 			    target_nid, MIGRATE_ASYNC, MR_DEMOTION,
 			    &nr_succeeded);
 
-- 
2.27.0