message: Disable MSAA when creating PSO for mesh output fetch on D3D12
  * This doesn't change anything as we're not rasterizing, but it keeps the D3D
  runtime happy.
diff: @@ -307,6 +307,10 @@ void D3D12Replay::InitPostVSBuffers(uint32_t eventId)
  // render as points
  psoDesc.PrimitiveTopologyType = D3D12_PRIMITIVE_TOPOLOGY_TYPE_POINT;
  + // disable MSAA
  + psoDesc.SampleDesc.Count = 1;
  + psoDesc.SampleDesc.Quality = 0;
  +
  // disable outputs
  RDCEraseEl(psoDesc.RTVFormats);
  psoDesc.DSVFormat = DXGI_FORMAT_UNKNOWN;
  