memcg: memcontrol whitespace cleanups

Sorry, before getting down to more important changes, I'd like to do some
cleanup in memcontrol.c.  This patch doesn't change the code generated, but
cleans up whitespace, moves up a double declaration, removes an unused enum,
removes void returns, removes misleading comments, that kind of thing.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hirokazu Takahashi <taka@valinux.co.jp>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>