Separate out slub sysfs removal and release, and call the former earlier
from __kmem_cache_shutdown().  There's no reason to defer sysfs removal
through RCU and this will later allow us to remove sysfs files way
earlier during memory cgroup offline instead of release.

Link: http://lkml.kernel.org/r/20170117235411.9408-3-tj@kernel.org

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>