vmscan: change type of vm_total_pages to unsigned long

This variable is calculated from nr_free_pagecache_pages so
change its type to unsigned long.

Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 606d0bb..88c5fed 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -128,7 +128,7 @@
  * From 0 .. 100.  Higher means more swappy.
  */
 int vm_swappiness = 60;
-long vm_total_pages;	/* The total number of pages which the VM controls */
+unsigned long vm_total_pages;	/* The total number of pages which the VM controls */
 
 static LIST_HEAD(shrinker_list);
 static DECLARE_RWSEM(shrinker_rwsem);