Fix racy memory usage in benchmark
Fix racy memory usage in benchmark

stealthly/go_kafka_client,lazyval/go_kafka_mirror,stealthly/go_kafka_client,lazyval/go_kafka_mirror,iobeam/go_kafka_client,iobeam/go_kafka_client,lazyval/go_kafka_mirror,elodina/go_kafka_client,CrowdStrike/go_kafka_client,iobeam/go_kafka_client,elodina/go_kafka_client,mistsys/go_kafka_client,CrowdStrike/go_kafka_client,mistsys/go_kafka_client,mistsys/go_kafka_client