sched/cpuacct: Initialize cpuacct subsystem earlier

Initialize cpuacct before the scheduler is functioning, so when
cpuacct_charge() and cpuacct_account_field() are called,
task_ca() won't return NULL.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/5155383F.8000005@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

kernel/sched/cpuacct.c

@@ -297,4 +297,5 @@ struct cgroup_subsys cpuacct_subsys = {
 	.css_free	= cpuacct_css_free,
 	.subsys_id	= cpuacct_subsys_id,
 	.base_cftypes	= files,
+	.early_init	= 1,
 };