touchpad: ignore motion on finger-up
It's unlikely to be possible for human to consciously change finger position and lift a finger so fast, that they fall into the same event. It's a spurious motion, ignore it.
Real world significance: subjectively scrolling/cursor positioning with a touchpad now a bit better on SAMSUNG NP305V5A laptop.
Signed-off-by: Konstantin Kharlamov Hi-Angel@yandex.ru