message: [dbus] fix typo
diff: @@ -529,7 +529,6 @@ otError DBusThreadObject::GetDeviceRoleHandler(DBusMessageIter &aIter)
  auto threadHelper = mNcp->GetThreadHelper();
  otDeviceRole role = otThreadGetDeviceRole(threadHelper->GetInstance());
  std::string roleName = GetDeviceRoleName(role);
  - ;
  otError error = OT_ERROR_NONE;
  VerifyOrExit(DBusMessageEncodeToVariant(&aIter, roleName) == OTBR_ERROR_NONE, error = OT_ERROR_INVALID_ARGS);
  