balloon: bz#1067249: device can't be removed when service is running
balloon: bz#1067249: device can't be removed when service is running

The service's HandlerEx callback function should return a value.

vrozenfe/kvm-guest-drivers-windows,YanVugenfirer/virtio-win-arm,YanVugenfirer/kvm-guest-drivers-windows,daynix/kvm-guest-drivers-windows,YanVugenfirer/virtio-win-arm,virtio-win/kvm-guest-drivers-windows,daynix/kvm-guest-drivers-windows,YanVugenfirer/kvm-guest-drivers-windows,YanVugenfirer/virtio-win-arm,virtio-win/kvm-guest-drivers-windows,daynix/kvm-guest-drivers-windows,YanVugenfirer/virtio-win-arm,YanVugenfirer/kvm-guest-drivers-windows,vrozenfe/kvm-guest-drivers-windows,YanVugenfirer/kvm-guest-drivers-windows,virtio-win/kvm-guest-drivers-windows,gnif/kvm-guest-drivers-windows,gnif/kvm-guest-drivers-windows,gnif/kvm-guest-drivers-windows,virtio-win/kvm-guest-drivers-windows,ladipro/kvm-guest-drivers-windows,daynix/kvm-guest-drivers-windows,vrozenfe/kvm-guest-drivers-windows,vrozenfe/kvm-guest-drivers-windows,virtio-win/kvm-guest-drivers-windows,ladipro/kvm-guest-drivers-windows,ladipro/kvm-guest-drivers-windows,ladipro/kvm-guest-drivers-windows,daynix/kvm-guest-drivers-windows,YanVugenfirer/kvm-guest-drivers-windows,vrozenfe/kvm-guest-drivers-windows,gnif/kvm-guest-drivers-windows