xcbutils: arm x apps can't be dragged to a negative position on the screen

the behavior of converting negative floating-point numbers to unsigned integers is undefined. It is necessary to keep the conversion behavior consistent between ARM and x86 platforms.

through the above conversions, all become the two's complement of negative numbers.

Signed-off-by: zorowk near.kingzero@gmail.com

(cherry picked from commit 904c3355)