message: Check Tensor ptr before accessing tensor->shape[channel_dim_index] to avoid segfault.
diff: @@ -249,11 +249,11 @@ TfLiteStatus SymmetricPerChannelQuantization(TensorT* tensor,
  std::vector<float>* output_scales,
  std::vector<int8_t>* output_value,
  ErrorReporter* error_reporter) {
  - const int32_t channel_dim_size = tensor->shape[channel_dim_index];
  if (tensor == nullptr) {
  error_reporter->Report("Cannot quantize. Tensor is null.");
  return kTfLiteError;
  }
  + const int32_t channel_dim_size = tensor->shape[channel_dim_index];
  // Fill per channel max and min values if needed
  if (tensor->quantization == nullptr) {
  tensor->quantization = absl::make_unique<QuantizationParametersT>();
  