x86: nmi_32.c cleanup - use for_each_online_cpu helper

Since cpu_online_map is touched (by for_each_online_cpu)
at moment when cpu_callin_map is already filled up we can
get rid of its checking at all

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: hpa@zytor.com
Cc: mingo@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/nmi_32.c

@@ -108,13 +108,7 @@ int __init check_nmi_watchdog(void)
 	local_irq_enable();
 	mdelay((20*1000)/nmi_hz); // wait 20 ticks
 
-	for_each_possible_cpu(cpu) {
-#ifdef CONFIG_SMP
-		/* Check cpu_callin_map here because that is set
-		   after the timer is started. */
-		if (!cpu_isset(cpu, cpu_callin_map))
-			continue;
-#endif
+	for_each_online_cpu(cpu) {
 		if (!per_cpu(wd_enabled, cpu))
 			continue;
 		if (nmi_count(cpu) - prev_nmi_count[cpu] <= 5) {