cgroup: minor cleanup for cgroup_extra_stat_show()

Make it under CONFIG_CGROUP_SCHED to rid of __maybe_unused annotation.
And further fetch cgrp inside cgroup_extra_stat_show() directly to rid
of __maybe_unused annotation of cgrp. No functional change intended.
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

kernel/cgroup/cgroup.c

@@ -3654,9 +3654,10 @@ static int cgroup_stat_show(struct seq_file *seq, void *v)
 	return 0;
 }
 
-static int __maybe_unused cgroup_extra_stat_show(struct seq_file *seq,
-						 struct cgroup *cgrp, int ssid)
+#ifdef CONFIG_CGROUP_SCHED
+static int cgroup_extra_stat_show(struct seq_file *seq, int ssid)
 {
+	struct cgroup *cgrp = seq_css(seq)->cgroup;
 	struct cgroup_subsys *ss = cgroup_subsys[ssid];
 	struct cgroup_subsys_state *css;
 	int ret;
@@ -3672,15 +3673,15 @@ static int __maybe_unused cgroup_extra_stat_show(struct seq_file *seq,
 	css_put(css);
 	return ret;
 }
+#endif
 
 static int cpu_stat_show(struct seq_file *seq, void *v)
 {
-	struct cgroup __maybe_unused *cgrp = seq_css(seq)->cgroup;
 	int ret = 0;
 
 	cgroup_base_stat_cputime_show(seq);
 #ifdef CONFIG_CGROUP_SCHED
-	ret = cgroup_extra_stat_show(seq, cgrp, cpu_cgrp_id);
+	ret = cgroup_extra_stat_show(seq, cpu_cgrp_id);
 #endif
 	return ret;
 }