Devices that send motion events with valuators other than x/y get core
motion events with unchanged x/y coordinates. This confuses some
applications.
If the DeviceEvent does not have the x/y valuators set, return BadMatch on
core conversion, thus skipping the event altogether.
Reported-by: Bartosz Brachaczek <b.brachaczek@gmail.com>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Tested-by: Bartosz Brachaczek <b.brachaczek@gmail.com>