memcg: fix mem_cgroup_rotate_reclaimable_page()

commit 3f58a8294333 ("move memcg reclaimable page into tail of inactive
list") added inline keyword twice in its prototype.

    CC      arch/x86/kernel/asm-offsets.s
  In file included from include/linux/swap.h:8,
                   from include/linux/suspend.h:4,
                   from arch/x86/kernel/asm-offsets.c:12:
  include/linux/memcontrol.h:220: error: duplicate `inline'

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 5a5ce70..5e9840f5 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -216,7 +216,7 @@
 	return ;
 }
 
-static inline inline void mem_cgroup_rotate_reclaimable_page(struct page *page)
+static inline void mem_cgroup_rotate_reclaimable_page(struct page *page)
 {
 	return ;
 }