message: Fix kafka message eof problem
diff: @@ -136,15 +136,16 @@ class KafkaDatasetOp : public DatasetOpKernel {
  return Status::OK();
  }
  - if (message->err() == RdKafka::ERR__PARTITION_EOF &&
  - dataset()->eof_) {
  - // EOF current topic
  - break;
  + if (message->err() == RdKafka::ERR__PARTITION_EOF) {
  + if (dataset()->eof_) break;
  }
  + else {
  if (message->err() != RdKafka::ERR__TIMED_OUT) {
  return errors::Internal("Failed to consume:",
  message->errstr());
  }
  + }
  +
  message.reset(nullptr);
  consumer_->poll(0);
  }
  