message: Set name of layer to node name when converting activation and FusedBatchNorm ops
  Also fix a potential crash if creating the layer fails.
diff: @@ -3783,6 +3783,7 @@ Status ConvertActivation(OpConverterParams* params) {
  params->converter->network()->addActivation(*inputs.at(0).tensor(),
  op_pair->second);
  TFTRT_RETURN_ERROR_IF_NULLPTR(layer, node_def.name());
  + layer->setName(node_def.name().c_str());
  // Set parameters.
  #if IS_TRT_VERSION_GE(5, 1, 2, 0)
  if (node_def.op() == "Elu") {
  @@ -3883,9 +3884,10 @@ Status ConvertRelu6(OpConverterParams* params) {
  nvinfer1::IActivationLayer* layer =
  params->converter->network()->addActivation(
  *inputs.at(0).tensor(), nvinfer1::ActivationType::kCLIP);
  + TFTRT_RETURN_ERROR_IF_NULLPTR(layer, node_def.name());
  layer->setAlpha(0.0f);
  layer->setBeta(6.0f);
  - TFTRT_RETURN_ERROR_IF_NULLPTR(layer, node_def.name());
  + layer->setName(node_def.name().c_str());
  nvinfer1::ITensor* output_tensor = layer->getOutput(0);
  params->converter->ProvideQuantizationRange(output_tensor, 0.0f, 6.0f);
  params->outputs->push_back(TRT_TensorOrWeights(output_tensor));
  @@ -4441,6 +4443,7 @@ Status ConvertUnary(OpConverterParams* params) {
  nvinfer1::IUnaryLayer* layer =
  params->converter->network()->addUnary(*tensor, op_pair->second);
  TFTRT_RETURN_ERROR_IF_NULLPTR(layer, node_def.name());
  + layer->setName(node_def.name().c_str());
  nvinfer1::ITensor* output_tensor = layer->getOutput(0);
  // Set quantization ranges.
  @@ -5089,6 +5092,7 @@ Status ConvertFusedBatchNorm(OpConverterParams* params) {
  combined_scale_weights.GetTrtWeights(),
  dummy_power_weights.GetTrtWeights());
  TFTRT_RETURN_ERROR_IF_NULLPTR(layer, node_def.name());
  + layer->setName(node_def.name().c_str());
  nvinfer1::ITensor* output_tensor = layer->getOutput(0);
  params->outputs->push_back(TRT_TensorOrWeights(output_tensor));
  return Status::OK();
  