CBQE-928: check_seqno after general verification

Change-Id: I6bff29457e9ef9dae927276c064baad50294250f
Reviewed-on: http://review.couchbase.org/24231
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>