KVM: PIT: Unregister ack notifier callback when freeing

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

arch/x86/kvm/i8254.c

@@ -672,6 +672,8 @@ void kvm_free_pit(struct kvm *kvm)
 	if (kvm->arch.vpit) {
 		kvm_unregister_irq_mask_notifier(kvm, 0,
 					       &kvm->arch.vpit->mask_notifier);
+		kvm_unregister_irq_ack_notifier(kvm,
+				&kvm->arch.vpit->pit_state.irq_ack_notifier);
 		mutex_lock(&kvm->arch.vpit->pit_state.lock);
 		timer = &kvm->arch.vpit->pit_state.pit_timer.timer;
 		hrtimer_cancel(timer);