ts problem in Xfbdev

[YongLi]

Hello All,

I found a problem with the hw\kdrive\linux\tslib.c TsRead function

On the touchscreen click release event, the ts_read function call get the
event with event.pressure=0, this TsRead function calls the KdEnqueuePointerEvent
 with x/y = previous point value. 

The KdEnqueuePointerEvent modify the pi->dixdev->last.valuators[] value with a wrong way:

click on (x, y) and release on (x+x, y+y).

Tyler Li