Merge branch 'for-3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup changes from Tejun Heo:
 "Three mostly trivial patches.  The biggest change is that blkio is now
  initialized before memcg which will be needed to make memcg and blkcg
  cooperate on writeback IOs"

* 'for-3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: add dummy css_put() for !CONFIG_CGROUPS
  cgroup: reorder SUBSYS(blkio) in cgroup_subsys.h
  Update of Documentation/cgroups/00-INDEX