mm: make mem_cgroup_resize_limit() static

Sparse output following warnings.

mm/memcontrol.c:782:5: warning: symbol 'mem_cgroup_resize_limit' 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/memcontrol.c

@@ -779,7 +779,8 @@ int mem_cgroup_shrink_usage(struct mm_struct *mm, gfp_t gfp_mask)
 	return 0;
 }
 
-int mem_cgroup_resize_limit(struct mem_cgroup *memcg, unsigned long long val)
+static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
+				   unsigned long long val)
 {
 
 	int retry_count = MEM_CGROUP_RECLAIM_RETRIES;