x86: add the word 'WARNING' in check_nmi_watchdog() output

Our automated test suite looks for keywords like error, fail, warning in
the boot log.  In the case when the nmi watchdog is determined to be
stuck in check_nmi_watchdog(), none of those keywords are displayed.

This patch adds a keyword, "WARNING:", so it makes it easier to notice
when the nmi watchdog isn't working correctly. Also add a proper
KERN_WARNING mark to this printout.
Signed-off-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/nmi_32.c

@@ -106,7 +106,8 @@ static int __init check_nmi_watchdog(void)
 		if (!per_cpu(wd_enabled, cpu))
 			continue;
 		if (nmi_count(cpu) - prev_nmi_count[cpu] <= 5) {
-			printk("CPU#%d: NMI appears to be stuck (%d->%d)!\n",
+			printk(KERN_WARNING "WARNING: CPU#%d: NMI "
+				"appears to be stuck (%d->%d)!\n",
 				cpu,
 				prev_nmi_count[cpu],
 				nmi_count(cpu));

arch/x86/kernel/nmi_64.c

@@ -109,7 +109,8 @@ int __init check_nmi_watchdog (void)
 		if (!per_cpu(wd_enabled, cpu))
 			continue;
 		if (cpu_pda(cpu)->__nmi_count - counts[cpu] <= 5) {
-			printk("CPU#%d: NMI appears to be stuck (%d->%d)!\n",
+			printk(KERN_WARNING "WARNING: CPU#%d: NMI "
+			       "appears to be stuck (%d->%d)!\n",
 			       cpu,
 			       counts[cpu],
 			       cpu_pda(cpu)->__nmi_count);