improve error checking for produce side failures
improve error checking for produce side failures

alfred-landrum/node-kafka-native,jut-io/node-kafka-native,jut-io/node-kafka-native,alfred-landrum/node-kafka-native,jut-io/node-kafka-native,alfred-landrum/node-kafka-native,jut-io/node-kafka-native,jut-io/node-kafka-native,alfred-landrum/node-kafka-native,alfred-landrum/node-kafka-native