Zipping the combined error-report.log file to disk overflow

Change-Id: Ia1e644b7343e28f566248ebfe7e768ed7b12a573
diff --git a/jjb/pipeline/voltha-dt-physical-functional-tests.groovy b/jjb/pipeline/voltha-dt-physical-functional-tests.groovy
index 43abe03..53a1a8a 100644
--- a/jjb/pipeline/voltha-dt-physical-functional-tests.groovy
+++ b/jjb/pipeline/voltha-dt-physical-functional-tests.groovy
@@ -205,6 +205,8 @@
       extract_errors_python voltha-ofagent >> $WORKSPACE/error-report.log
       extract_errors_python onos >> $WORKSPACE/error-report.log
 
+      gzip error-report.log || true
+
       cd $WORKSPACE/voltha/kind-voltha/scripts/logger/combined/
       tar czf $WORKSPACE/container-logs.tgz *