[POWERPC] pasemi: Fix NMI handling check

The logic that checks to see if a machine check is caused by an NMI will
always match when NMI hasn't been initialized, since the mpic routine
will return NO_IRQ (and that's what the nmi_virq value is as well).

Signed-off-by: Olof Johansson <olof@lixom.net>
diff --git a/arch/powerpc/platforms/pasemi/setup.c b/arch/powerpc/platforms/pasemi/setup.c
index 1940e67..a89d098 100644
--- a/arch/powerpc/platforms/pasemi/setup.c
+++ b/arch/powerpc/platforms/pasemi/setup.c
@@ -264,7 +264,7 @@
 	srr0 = regs->nip;
 	srr1 = regs->msr;
 
-	if (mpic_get_mcirq() == nmi_virq) {
+	if (nmi_virq != NO_IRQ && mpic_get_mcirq() == nmi_virq) {
 		printk(KERN_ERR "NMI delivered\n");
 		debugger(regs);
 		mpic_end_irq(nmi_virq);