cgroup: fix build when CGROUP_SCHED is not enabled

Sudip Mukherjee reports that the mips sb1250_swarm_defconfig build fails
with the current kernel.  It isn't actually MIPS-specific, it's just
that that defconfig does not have CGROUP_SCHED enabled like most configs
do, and as such shows this error:

  kernel/cgroup/cgroup.c: In function 'cgroup_local_stat_show':
  kernel/cgroup/cgroup.c:3699:15: error: implicit declaration of function 'cgroup_tryget_css'; did you mean 'cgroup_tryget'? [-Werror=implicit-function-declaration]
   3699 |         css = cgroup_tryget_css(cgrp, ss);
        |               ^~~~~~~~~~~~~~~~~
        |               cgroup_tryget
  kernel/cgroup/cgroup.c:3699:13: warning: assignment to 'struct cgroup_subsys_state *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
   3699 |         css = cgroup_tryget_css(cgrp, ss);
        |             ^

because cgroup_tryget_css() only exists when CGROUP_SCHED is enabled,
and the cgroup_local_stat_show() function should similarly be guarded by
that config option.

Move things around a bit to fix this all.

Fixes: d1d4ff5d ("cgroup: put cgroup_tryget_css() inside CONFIG_CGROUP_SCHED")
Reported-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/cgroup/cgroup.c

@@ -3673,20 +3673,8 @@ static int cgroup_extra_stat_show(struct seq_file *seq, int ssid)
 	css_put(css);
 	return ret;
 }
-#endif
-
-static int cpu_stat_show(struct seq_file *seq, void *v)
-{
-	int ret = 0;
-
-	cgroup_base_stat_cputime_show(seq);
-#ifdef CONFIG_CGROUP_SCHED
-	ret = cgroup_extra_stat_show(seq, cpu_cgrp_id);
-#endif
-	return ret;
-}
 
-static int __maybe_unused cgroup_local_stat_show(struct seq_file *seq,
+static int cgroup_local_stat_show(struct seq_file *seq,
 				  struct cgroup *cgrp, int ssid)
 {
 	struct cgroup_subsys *ss = cgroup_subsys[ssid];
@@ -3704,6 +3692,18 @@ static int __maybe_unused cgroup_local_stat_show(struct seq_file *seq,
 	css_put(css);
 	return ret;
 }
+#endif
+
+static int cpu_stat_show(struct seq_file *seq, void *v)
+{
+	int ret = 0;
+
+	cgroup_base_stat_cputime_show(seq);
+#ifdef CONFIG_CGROUP_SCHED
+	ret = cgroup_extra_stat_show(seq, cpu_cgrp_id);
+#endif
+	return ret;
+}
 
 static int cpu_local_stat_show(struct seq_file *seq, void *v)
 {