wined3d/d3d9: Set the initial scissor rect to the window size

[Stefan Dösinger]

I think you don't have to test a 2nd swapchain here. The initial scissor rectangle is set in CreateDevice, so an extra call to CreateAdditionalSwapchain afterwards shouldn't have any effect on this. I am mainly concerned by the open source drivers here which do not always like messing with OpenGL contexts too much. I am afraid we'll get complaints that the test crashes or even causes a kernel panic :-/.

Does "WINED3DSURFACE_DESC desc = {0};" set all the pointers in WINED3DSURFACEDESC to NULL? I am not sure about this. (At some point we may also want to de-pointerize WINED3DSURFACEDESC like we've done with the other structures)