[PATCH cgroup/for-4.15] cgroup: statically initialize init_css_set->dfl_cgrp

From: Tejun Heo
Date: Mon Sep 25 2017 - 17:10:41 EST

Hello,

A follow-up patch to fix sporadic oops during boot which is caused by
trying dereference the default cgroup from accounting code before
cgroup is initialized.

Applied to cgroup/for-4.15.

Thanks.
------ 8< ------