We weren't cancelling the old timer when changing cursors, making things
go all crashy. Logically we could always cancel the timer first, but
then we'd have to call TimerSet to re-arm ourselves, and GetTimeInMillis
is potentially expensive.
Reported-by: https://devtalk.nvidia.com/default/topic/1028172/linux/titan-v-ubuntu-16-04lts-and-387-34-driver-crashes-badly/post/5230967/#5230967
Signed-off-by: Adam Jackson <ajax@redhat.com>
Reviewed-by: Aaron Plattner <aplattner@nvidia.com>
Tested-by: Aaron Plattner <aplattner@nvidia.com>