fix regression where traces were never written to files
fix regression where traces were never written to files

shibayan/kudu,projectkudu/kudu,shibayan/kudu,projectkudu/kudu,projectkudu/kudu,shibayan/kudu,shibayan/kudu,EricSten-MSFT/kudu,projectkudu/kudu,EricSten-MSFT/kudu,EricSten-MSFT/kudu,projectkudu/kudu,EricSten-MSFT/kudu,shibayan/kudu,EricSten-MSFT/kudu