mm/vmstat: Drop get_online_cpus() from init_cpu_node_state/vmstat_cpu_dead()

Both functions are called with protection against cpu hotplug already so
*_online_cpus() could be dropped.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: linux-mm@kvack.org
Cc: rt@linutronix.de
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Link: http://lkml.kernel.org/r/20161126231350.10321-8-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

mm/vmstat.c

@@ -1722,24 +1722,19 @@ static void __init init_cpu_node_state(void)
 {
 	int cpu;
 
-	get_online_cpus();
 	for_each_online_cpu(cpu)
 		node_set_state(cpu_to_node(cpu), N_CPU);
-	put_online_cpus();
 }
 
 static void vmstat_cpu_dead(int node)
 {
 	int cpu;
 
-	get_online_cpus();
 	for_each_online_cpu(cpu)
 		if (cpu_to_node(cpu) == node)
-			goto end;
+			return;
 
 	node_clear_state(node, N_CPU);
-end:
-	put_online_cpus();
 }
 
 /*