message: really don't init per-thread GPU realloc buffer if using the CNN
diff: @@ -924,6 +924,7 @@ void threads_at_work(job_queue<worker_job>* wrkq,
  {
  if (gs->settings->gpu_on) {
  initializeCUDA(gs->settings->device);
  + if (!(gs->cnnopts.cnn_scoring || gs->cnnopts.cnn_refinement))
  thread_buffer.init(free_mem(gs->settings->cpu));
  }
  