kernel32/tests: Explicitly cast to signed char

[Dmitry Timoshkov]

André Hentschel <nerv at dawncrow.de> wrote:

> -    ok(mbc == -28, "mbc is %d\n", mbc);
> +    ok((signed char)mbc == -28, "mbc is %d\n", mbc);
>      if(bUsedDefaultChar) ok(*bUsedDefaultChar == FALSE, "bUsedDefaultChar is %d\n", *bUsedDefaultChar);
>      ok(GetLastError() == 0xdeadbeef, "GetLastError() is %u\n", GetLastError());
>  
> @@ -301,7 +301,7 @@ static void test_string_conversion(LPBOOL bUsedDefaultChar)
>          SetLastError(0xdeadbeef);
>          ret = WideCharToMultiByte(1251, 0, &wc2, 1, &mbc, 1, NULL, bUsedDefaultChar);
>          ok(ret == 1, "ret is %d\n", ret);
> -        ok(mbc == -16, "mbc is %d\n", mbc);
> +        ok((signed char)mbc == -16, "mbc is %d\n", mbc);

In these cases comparison with hex would work better IMO, and printing
the result of conversion in hex would be more readable as well.

-- 
Dmitry.