CBQE-0: fix string formatting argument

Change-Id: If6098f562aaf4a48a5eb6851edad87034827c258
Reviewed-on: http://review.couchbase.org/37189
Reviewed-by: Sangharsh Agarwal <sangharsh.agarwal@globallogic.com>
Tested-by: Sangharsh Agarwal <sangharsh.agarwal@globallogic.com>