message: Fix null-AUC in using a single GPU
diff: @@ -305,7 +305,7 @@ Error_t SessionImpl<TypeKey>::eval() {
  gpu_resource_group_->results[i].get();
  }
  } else if (networks_eval_.size() == 1) {
  - networks_eval_[0]->eval();
  + network_eval_helper(0, networks_eval_[0].get(), metrics_);
  } else {
  assert(!"networks_eval_.size() should not less than 1.");
  }
  