mm: memcg: remove needless !mm fixup to init_mm when charging
mm: memcg: remove needless !mm fixup to init_mm when charging

It does not matter to __mem_cgroup_try_charge() if the passed mm is NULL
or init_mm, it will charge the root memcg in either case.

Also fix up the comment in __mem_cgroup_try_charge() that claimed the
init_mm would be charged when no mm was passed.  It's not really
incorrect, but confusing.  Clarify that the root memcg is charged in this
case.

Signed-off-by: Johannes Weiner <331be22c6b63ca3e0a03d408c2d906b1b02cd5f2@cmpxchg.org>
Acked-by: KAMEZAWA Hiroyuki <634f508bd7c47cf0ee4126243675c3e598920fbc@jp.fujitsu.com>
Acked-by: Michal Hocko <829500b200af6c2a0eca4dfd5c388e6b8fbe8dc6@suse.cz>
Cc: David Rientjes <d8cd2994e15bc61ddb2b113030bda55eebc3a0fe@google.com>
Cc: Hugh Dickins <d3abdf3e2800e6cb849f11b81e6eb50b34d96431@google.com>
Cc: Johannes Weiner <331be22c6b63ca3e0a03d408c2d906b1b02cd5f2@cmpxchg.org>
Cc: Wanpeng Li <939b2a9d2b69b207710f647df194ddcff6a29d20@gmail.com>
Cc: Mel Gorman <2f629c4d93e35c3d371f0463b040c6ef04a5c1e5@csn.ul.ie>
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,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs