comctl32: Avoid magic numbers

[Nikolay Sivov]

>    /* FIXME: This flag is undocumented and unknown by our CompareString.
> -   *        We need a define for it.
>     */
> -  dwFlags = 0x10000000;
> +  dwFlags = LOCALE_RETURN_GENITIVE_NAMES;
>    if (!bCase) dwFlags |= NORM_IGNORECASE;

It makes no sense to use this flag from CompareString(). I think it's 
better to remove it along with this comment.