dlls/msi/string.c -- fix use of signed versus unsigned (RESEND)

[Gerald Pfeifer]

On Thu, 15 Nov 2007, James Hawkins wrote:
> I don't see how silencing warnings catches any regression.

With default options older versions of GCC currently issue two warnings 
for all of Wine, so any warning regression immediately jumps out for 
analysis to see whether it is a real regression.  If instead of two the 
base is 2000, just another one is easy to miss.  That's the experience
we made with GCC, and some other projects I have worked on.

> If you really want to keep sending in patches for these warnings,
> please be more conservative.  Unsigned comparisons for less than 0
> are actual bugs, so you can be sure about those

I actually plan to focus on those.  There are about fifty left.  Just
for patches I have sent already or on my disk it would be nice to see
those considered because I did invest time on those.

Gerald