It held a raw pointer to a IOS::HLE::Device::BluetoothEmu that is not
guaranteed to exist (and of course, nothing checked that it wasn't
nullptr), but what is more, it's totally unnecessary because we have
IOS::HLE::GetDeviceByName().
Since we cannot always inform the host that Wii remotes are
disconnected from ES, that is now done in BluetoothEmu's destructor.