ddraw/tests: Skip some tests when switching the display mode is not supported.

[Henri Verbeet]

On 17 February 2014 17:45, Francois Gouget <fgouget at codeweavers.com> wrote:
> This can happen on Windows 8 when the 'Microsoft Basic Display Adapter' driver does not recognize the graphics card, for instance QEmu's 'vga' graphics card.

As mentioned earlier on IRC, I think that setup is broken for the
purpose of running the tests.