Fix snprintfW Return Value

[Alexandre Julliard]

Rob Shearman <rob at codeweavers.com> writes:

> At present, if the size of the buffer passed to snprintfW is too small
> then the function returns -1, as opposed to the required size of the
> buffer (as per C snprintf). This greatly limits its usefulness and can
> give incorrect results for those using the function that don't
> explicitly check for -1 being returned. A grep of the source tree shows
> that nothing depends on this behaviour.

Actually, something does depend on it: it is used to implement
_vsnwprintf in ntdll, so you can't change it.

-- 
Alexandre Julliard
julliard at winehq.org