KVM: ia64: destroy ioapic device if fail to setup default irq routing

If KVM_CREATE_IRQCHIP fail due to kvm_setup_default_irq_routing(),
ioapic device is not destroyed and kvm->arch.vioapic is not set to
NULL, this may cause KVM_GET_IRQCHIP and KVM_SET_IRQCHIP access to
unexcepted memory.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index 0618898..26e0e08 100644
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -968,7 +968,7 @@
 			goto out;
 		r = kvm_setup_default_irq_routing(kvm);
 		if (r) {
-			kfree(kvm->arch.vioapic);
+			kvm_ioapic_destroy(kvm);
 			goto out;
 		}
 		break;