Removing the zipped log form the tucson pipeline before starting the new logging

Change-Id: I1522933905588fbfd64f7e489bd41cdb738b2cbc
diff --git a/jjb/pipeline/voltha/master/tucson-build-and-test.groovy b/jjb/pipeline/voltha/master/tucson-build-and-test.groovy
index 3c3b942..af568da 100644
--- a/jjb/pipeline/voltha/master/tucson-build-and-test.groovy
+++ b/jjb/pipeline/voltha/master/tucson-build-and-test.groovy
@@ -138,6 +138,7 @@
           }
           // start logging
           sh """
+          rm -rf $WORKSPACE/${workFlow}/
           mkdir -p $WORKSPACE/${workFlow}
           _TAG=kail-${workFlow} kail -n infra -n voltha > $WORKSPACE/${workFlow}/onos-voltha-combined.log &
           """