hs-test: fix vppinstance logs and disable trace

- fixed a bug where vppinstance logs would concatenate -> each test now
  has its own bind mount
- removed "--trace" flag to avoid skipped tests printing a full
  stack trace. They are now only printed in the summary.

Type: test

Change-Id: Ib7f4254717cc798e456b9fca6f81685c8153ee2d
Signed-off-by: Adrian Villin <avillin@cisco.com>

extras/hs-test/script/compress.sh

@@ -11,7 +11,7 @@ then
             logDir=/tmp/hs-test/$dirName
             if [ -d "$logDir" ]; then
                 mkdir -p ${WORKSPACE}/archives/summary
-                cp -r $logDir ${WORKSPACE}/archives/summary/
+                rsync -a --exclude 'volumes' $logDir ${WORKSPACE}/archives/summary/
             fi
         done
         echo "Done."