CBQE-0: delete unnecessary checks per MB-9172

Change-Id: Ibf6e867301cd39c7c487b52f2d171b865f255785
Reviewed-on: http://review.couchbase.org/33396
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>
Tested-by: Iryna Mironava <irynamironava@yandex.ru>