Input: goodix - fix spurious key release events

Input: goodix - fix spurious key release events

The goodix panel sends spurious interrupts after a 'finger up' event,
which always cause a timeout.
We were exiting the interrupt handler by reporting touch_num == 0, but
this was still processed as valid and caused the code to use the
uninitialised point_data, creating spurious key release events.

Report an error from the interrupt handler so as to avoid processing
invalid point_data further.

Signed-off-by: Dmitry Mastykin <dmastykin@astralinux.ru>
Reviewed-by: Bastien Nocera <hadess@hadess.net>
Link: https://lore.kernel.org/r/20200316075302.3759-2-dmastykin@astralinux.ru
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>