HID: wacom: Use ktime_t rather than int when dealing with timestamps

In the Linux kernel, the following vulnerability has been resolved: HID: wacom: Use ktime_t rather than int when dealing with timestamps Code which interacts with timestamps needs to use the ktime_t type returned by functions like ktime_get. The int type does not offer enough space to store these values, and attempting to use it is a recipe for problems. In this particular case, overflows would occur when calculating/storing timestamps leading to incorrect values being reported to userspace. In some cases these bad timestamps cause input handling in userspace to appear hung.