Add missing break to switch-case block

The case label for VIR_DOMAIN_EVENT_ID_DEVICE_REMOVED did not have its
own break statement but relied on falling through which we probably
don't want.

libvirt-override.c

@@ -6399,6 +6399,7 @@ libvirt_virConnectDomainEventRegisterAny(ATTRIBUTE_UNUSED PyObject * self,
         break;
     case VIR_DOMAIN_EVENT_ID_DEVICE_REMOVED:
         cb = VIR_DOMAIN_EVENT_CALLBACK(libvirt_virConnectDomainEventDeviceRemovedCallback);
+        break;
 
     case VIR_DOMAIN_EVENT_ID_LAST:
         break;