These don't report ABS_X/ABS_Y, but are still a touchscreen. This is commonly
seen on Android hardware.
As a bonus, we clean up the flow control through device discovery: by using
memset, we can ignore the error value of ioctl() and just check the bits we
need.
We can also close() the FD instantly after running the ioctl calls.
Change-Id: I6405597dc34841c805552fa73ef86250eaae111c
Reviewed-by: Laszlo Agocs <laszlo.agocs@theqtcompany.com>
2f83e38bfc