Fix xwiidump error path
Fix xwiidump error path

Return EXIT_FAILURE if device cannot be opened. Also remove NUM as it was not
supported. We always read only one byte, otherwise we might get gaps in the
output.

Signed-off-by: David Herrmann <fb53b2ddb8d141e0cb39d7c67c2f81b6bc2eb0f7@googlemail.com>

barracks510/xwiimote,dvdhrm/xwiimote,dvdhrm/xwiimote,AdamLuchjenbroers/xwiimote,AdamLuchjenbroers/xwiimote,barracks510/xwiimote,barracks510/xwiimote,barracks510/xwiimote