comctl32/tests: Fix couple of metrics tests that fail on some systems

[Dmitry Timoshkov]

Nikolay Sivov <nsivov at codeweavers.com> wrote:

> +    /* estimate using stock font metrics */
> +    hdc = GetDC(0);
> +    hOldFont = SelectObject(hdc, GetStockObject (SYSTEM_FONT));
> +    GetTextMetricsA(hdc, &tm);
> +    SelectObject(hdc, hOldFont);
> +    ReleaseDC(0, hdc);

Probably DEFAULT_GUI_FONT should be used instead of SYSTEM, you really
don't want to see SYSTEM_FONT on the screen, or just use its metrics.

-- 
Dmitry.