message: Update mlir_tf2xla.cc
diff: @@ -140,9 +140,9 @@ Status ConvertGraphDefToXlaViaMlir(
  if (!debug_info_path_begin_marker.empty()) {
  for (size_t i = 0, e = debug_info.files_size(); i < e; ++i) {
  std::string* file_name = debug_info.mutable_files(i);
  - int location =
  + size_t location =
  file_name->rfind(std::string(debug_info_path_begin_marker));
  - if (location != -1) {
  + if (location != std::string::npos) {
  *file_name = file_name->substr(location +
  debug_info_path_begin_marker.length());
  }
  