Get rid of a deprecated librdkafka function.

src/mq/kafka/mq.c

@@ -352,7 +352,7 @@ MQ_Send(void *priv, const char *data, unsigned len, const char *key,
     if (rd_kafka_produce(wrk->topic, RD_KAFKA_PARTITION_UA, RD_KAFKA_MSG_F_FREE,
                          payload, len, key, keylen, NULL) == -1) {
         snprintf(wrk->errmsg, LINE_MAX, "%s",
-                 rd_kafka_err2str(rd_kafka_errno2err(errno)));
+                 rd_kafka_err2str(rd_kafka_last_error()));
         MQ_LOG_Log(LOG_ERR, "%s message send failure (%d): %s",
                    rd_kafka_name(wrk->kafka), errno, wrk->errmsg);
         *error = wrk->errmsg;

src/mq/kafka/worker.c

@@ -93,10 +93,9 @@ const char
     CHECK_OBJ_NOTNULL((kafka_wrk_t *) rd_kafka_opaque(rk), KAFKA_WRK_MAGIC);
     rd_kafka_set_log_level(rk, loglvl);
 
-    errno = 0;
     rkt = rd_kafka_topic_new(rk, topic, wrk_topic_conf);
     if (rkt == NULL) {
-        rd_kafka_resp_err_t rkerr = rd_kafka_errno2err(errno);
+        rd_kafka_resp_err_t rkerr = rd_kafka_last_error();
         snprintf(errmsg, LINE_MAX, "Failed to initialize topic: %s",
                  rd_kafka_err2str(rkerr));
         MQ_LOG_Log(LOG_ERR, errmsg);