mm: make scan_all_zones_unevictable_pages() static

sparse output following warning.

	mm/vmscan.c:2549:6: warning: symbol 'scan_all_zones_unevictable_pages' was not declared. Should it be static?

cleanup here.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/vmscan.c

diff --git a/mm/vmscan.c b/mm/vmscan.c
index da7c3a2..062767d 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2506,7 +2506,7 @@
  * that has possibly/probably made some previously unevictable pages
  * evictable.
  */
-void scan_all_zones_unevictable_pages(void)
+static void scan_all_zones_unevictable_pages(void)
 {
 	struct zone *zone;