d3d8/tests: make sure to use return values (LLVM/Clang)

[Jacek Caban]

Hi Austin,

     ok(SUCCEEDED(hr), "GetRenderTarget failed, hr %#x.\n", hr);
     hr = IDirect3DSurface8_GetDesc(surface, &surface_desc);
+    ok(SUCCEEDED(hr), "GetDesc failed, hr %#x.\n", hr);


It's better to test for the exact value in tests like hr == S_OK. It
makes tests stricter. I know there are already tests checking
SUCCEEDED(), but while you are at this, let's get it right.

Also, patches should go to wine-patches ;)


Jacek