memcg: stop warning on memcg_propagate_kmem

Whilst I run the risk of a flogging for disloyalty to the Lord of Sealand,
I do have CONFIG_MEMCG=y CONFIG_MEMCG_KMEM not set, and grow tired of the
"mm/memcontrol.c:4972:12: warning: `memcg_propagate_kmem' defined but not
used [-Wunused-function]" seen in 3.8-rc: move the #ifdef outwards.
Signed-off-by: NHugh Dickins <hughd@google.com>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Cc: Glauber Costa <glommer@parallels.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mm/memcontrol.c

@@ -5025,6 +5025,7 @@ static int memcg_update_kmem_limit(struct cgroup *cont, u64 val)
 	return ret;
 }
 
+#ifdef CONFIG_MEMCG_KMEM
 static int memcg_propagate_kmem(struct mem_cgroup *memcg)
 {
 	int ret = 0;
@@ -5033,7 +5034,6 @@ static int memcg_propagate_kmem(struct mem_cgroup *memcg)
 		goto out;
 
 	memcg->kmem_account_flags = parent->kmem_account_flags;
-#ifdef CONFIG_MEMCG_KMEM
 	/*
 	 * When that happen, we need to disable the static branch only on those
 	 * memcgs that enabled it. To achieve this, we would be forced to
@@ -5059,10 +5059,10 @@ static int memcg_propagate_kmem(struct mem_cgroup *memcg)
 	mutex_lock(&set_limit_mutex);
 	ret = memcg_update_cache_sizes(memcg);
 	mutex_unlock(&set_limit_mutex);
-#endif
 out:
 	return ret;
 }
+#endif /* CONFIG_MEMCG_KMEM */
 
 /*
  * The user of this function is...