wined3d: Don't use filtering on textures that need complex fixups in swapchain_blit().

For example, interpolating palette indices doesn't have the desired result.
Should we really want filtering for these cases we could implement it inside
the relevant shaders, after the fixup, but I doubt it's worth the effort.

dlls/wined3d/swapchain.c

@@ -152,6 +152,9 @@ static void swapchain_blit(IWineD3DSwapChainImpl *This, struct wined3d_context *
             tex_bottom /= src_h;
         }
 
+        if (is_complex_fixup(backbuffer->resource.format_desc->color_fixup))
+            gl_filter = GL_NEAREST;
+
         ENTER_GL();
         context_bind_fbo(context2, GL_DRAW_FRAMEBUFFER, NULL);