Merge "RootCanal: Fix sign of printf format"

  std::vector<uint8_t> output;

  output.resize(device_name_len + 1);

  int written_len = std::snprintf(reinterpret_cast<char*>(output.data()),

                                  output.size(), "#%02zd device", device_nr);

                                  output.size(), "#%02zu device", device_nr);

  // Remove the null terminator, not used for the device name

  // since it is framed in most cases.

  output.resize(device_name_len);