[d3d8] Fix CreateImageSurface implementation (with testcase)

[Tobias Jakobi]

(I think this belongs into wine-devel, sorry for also posting this on 
wine-patches)

Oops, sorry! I corrected the mixed indentation style (must have been the 
copy&paste).

However I think the comment should stay there. I don't think the MSDN 
docs are updated in the near future, at least what D3D9 is concerned 
(now that D3D10 is more and more used). So in case someone is wondering 
why the implementation of wine differs from the behaviour described in 
the MSDN this comment should clarify this.

Now should I also add something about the scratch pool type?

Greets,
Tobias