KVM: PPC: Check max IRQ prio

We have a define on what the highest bit of IRQ priorities is. So we can
just as well use it in the bit checking code and avoid invalid IRQ values
to be triggered.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 61ae0fa..ec0a651 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -337,7 +337,7 @@
 		printk(KERN_EMERG "KVM: Check pending: %lx\n", vcpu->arch.pending_exceptions);
 #endif
 	priority = __ffs(*pending);
-	while (priority <= (sizeof(unsigned int) * 8)) {
+	while (priority < BOOK3S_IRQPRIO_MAX) {
 		if (kvmppc_book3s_irqprio_deliver(vcpu, priority) &&
 		    (priority != BOOK3S_IRQPRIO_DECREMENTER)) {
 			/* DEC interrupts get cleared by mtdec */