memcg: fix off-by-one when calculating swap cgroup map length
memcg: fix off-by-one when calculating swap cgroup map length

It allocated one more page than necessary if @max_pages was a multiple of
SC_PER_PAGE.

Signed-off-by: Namhyung Kim <5c915a589b3ddf58cebf14bec41bcc143b37ac3c@gmail.com>
Acked-by: KAMEZAWA Hiroyuki <634f508bd7c47cf0ee4126243675c3e598920fbc@jp.fujitsu.com>
Acked-by: Balbir Singh <65a1aed538f36fed73d8c45e9ddfc585ce9f4abf@linux.vnet.ibm.com>
Cc: Daisuke Nishimura <d7ce9d9454f80efacebffaaa82023b8c983997f5@mxp.nes.nec.co.jp>
Cc: Michal Hocko <829500b200af6c2a0eca4dfd5c388e6b8fbe8dc6@suse.cz>
Signed-off-by: Andrew Morton <5c1e68b099950c134891f0b6e179498a8ebe9cf9@linux-foundation.org>
Signed-off-by: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs