message: [ot-client] fix bug in stripping `Done\r\n`
diff: @@ -158,7 +158,7 @@ char *OpenThreadClient::Execute(const char *aFormat, ...)
  if (done != nullptr)
  {
  // remove trailing \r\n
  - if (done - rval > 2)
  + if (done - mBuffer > 2)
  {
  done[-2] = '\0';
  }
  