CBQE-0: fix verify_xdcr_stats function call after removing verify_src parameter

Change-Id: Id290aa0172b75b70f4ff9cb0cea545d97b351dba
Reviewed-on: http://review.couchbase.org/41123
Reviewed-by: Sangharsh Agarwal <sangharsh.agarwal@globallogic.com>
Tested-by: Sangharsh Agarwal <sangharsh.agarwal@globallogic.com>