X11DRV: Fix signed/unsigned comparison warnings

[Alexandre Julliard]

Hans Leidekker <hans at it.vu.nl> writes:

> Changelog:
>   Fix signed/unsigned comparison warnings

A number of these changes are wrong. Please be more careful when doing
that sort of thing, only change the ones you are absolutely sure
about. We don't want to introduce bugs just to silence warnings.

-- 
Alexandre Julliard
julliard at winehq.org