wined3d: Fix bug in swapchain release which causes incorrect display mode changes.

[Chris Robinson]

On Saturday 16 February 2008 06:01:48 am Peter Dons Tychsen wrote:
> Fixed bug in wined3d swapchain, which caused the release of the
> swap-chain to mess around with the display-modes set by ddraw. Also
> added test-case for this scenario. Reworked test code minimally, to
> re-use existing test code.

You may want to test D3D8 and D3D9 too, to see what they do when presented by 
the situation (since the code is shared). Also I don't think you should make 
those 2-space indents just to avoid changing those few lines.