KVM: PPC: add missing pt_regs initialization

On this switch branch the regs initialization
doesn't happen so add it.
This was found with the help of a static
code analysis tool.

Signed-off-by: Laurentiu Tudor <Laurentiu.Tudor@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

arch/powerpc/kvm/booke.c

@@ -933,6 +933,7 @@ static void kvmppc_restart_interrupt(struct kvm_vcpu *vcpu,
 #endif
 		break;
 	case BOOKE_INTERRUPT_CRITICAL:
+		kvmppc_fill_pt_regs(&regs);
 		unknown_exception(&regs);
 		break;
 	case BOOKE_INTERRUPT_DEBUG: