x86: check with without_new in show_interrupts

so we don't get new one that we don't need it.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c
index f58b995..f337f87 100644
--- a/arch/x86/kernel/irq_64.c
+++ b/arch/x86/kernel/irq_64.c
@@ -83,7 +83,10 @@
 
 	if (i < nr_irqs) {
 		unsigned any_count = 0;
-		struct irq_desc *desc = irq_to_desc(i);
+		struct irq_desc *desc = __irq_to_desc(i);
+
+		if (!desc)
+			return 0;
 
 		spin_lock_irqsave(&desc->lock, flags);
 #ifndef CONFIG_SMP