wined3d: Don't touch "ppSurface" on failure in IWineD3DDeviceImpl_CreateSurface().

I originally kept these when adding surface_init() in
5f581975dc because the original code had them on
most error paths. However, this actually broke ddraw because it assumed we
don't touch "ppSurface" on errors. Just remove these since they're useless
anyway.

dlls/wined3d/device.c

@@ -640,7 +640,6 @@ static HRESULT WINAPI IWineD3DDeviceImpl_CreateSurface(IWineD3DDevice *iface, UI
     if (!object)
     {
         ERR("Failed to allocate surface memory.\n");
-        *ppSurface = NULL;
         return WINED3DERR_OUTOFVIDEOMEMORY;
     }
 
@@ -650,7 +649,6 @@ static HRESULT WINAPI IWineD3DDeviceImpl_CreateSurface(IWineD3DDevice *iface, UI
     {
         WARN("Failed to initialize surface, returning %#x.\n", hr);
         HeapFree(GetProcessHeap(), 0, object);
-        *ppSurface = NULL;
         return hr;
     }