Turns out switching from 'size_t' to 'int' created different warnings.
Using 'unsigned int' solves all warnings.

Change-Id: I2c6c96fe6ed881bb6ce63717d53c8c5864273157
Reviewed-on: https://swiftshader-review.googlesource.com/5702Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>