improved device handling in device_removal_callback
improved device handling in device_removal_callback

jrolfs/Karabiner-Elements,tekezo/Karabiner-Elements,jrolfs/Karabiner-Elements,jrolfs/Karabiner-Elements,jrolfs/Karabiner-Elements,tekezo/Karabiner-Elements,tekezo/Karabiner-Elements,tekezo/Karabiner-Elements