CBQE-0: fix clean up of test case

Change-Id: Ib30866bbf4a7fb6004347915271b19928bd7cef3
Reviewed-on: http://review.couchbase.org/37421
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Parag Agarwal <agarwal.parag@gmail.com>
Tested-by: Parag Agarwal <agarwal.parag@gmail.com>