cgroup: convert all non-memcg controllers to the new cftype interface

Convert debug, freezer, cpuset, cpu_cgroup, cpuacct, net_prio, blkio,
net_cls and device controllers to use the new cftype based interface.
Termination entry is added to cftype arrays and populate callbacks are
replaced with cgroup_subsys->base_cftypes initializations.

This is functionally identical transformation.  There shouldn't be any
visible behavior change.

memcg is rather special and will be converted separately.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <paul@paulmenage.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Vivek Goyal <vgoyal@redhat.com>
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 4603b9d..afc6d7e 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7970,13 +7970,9 @@
 		.write_u64 = cpu_rt_period_write_uint,
 	},
 #endif
+	{ }	/* terminate */
 };
 
-static int cpu_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cont)
-{
-	return cgroup_add_files(cont, ss, cpu_files, ARRAY_SIZE(cpu_files));
-}
-
 struct cgroup_subsys cpu_cgroup_subsys = {
 	.name		= "cpu",
 	.create		= cpu_cgroup_create,
@@ -7984,8 +7980,8 @@
 	.can_attach	= cpu_cgroup_can_attach,
 	.attach		= cpu_cgroup_attach,
 	.exit		= cpu_cgroup_exit,
-	.populate	= cpu_cgroup_populate,
 	.subsys_id	= cpu_cgroup_subsys_id,
+	.base_cftypes	= cpu_files,
 	.early_init	= 1,
 };
 
@@ -8170,13 +8166,9 @@
 		.name = "stat",
 		.read_map = cpuacct_stats_show,
 	},
+	{ }	/* terminate */
 };
 
-static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)
-{
-	return cgroup_add_files(cgrp, ss, files, ARRAY_SIZE(files));
-}
-
 /*
  * charge this task's execution time to its accounting group.
  *
@@ -8208,7 +8200,7 @@
 	.name = "cpuacct",
 	.create = cpuacct_create,
 	.destroy = cpuacct_destroy,
-	.populate = cpuacct_populate,
 	.subsys_id = cpuacct_subsys_id,
+	.base_cftypes = files,
 };
 #endif	/* CONFIG_CGROUP_CPUACCT */