CBQE-1296 Fix error in BucketCreateTask::check

Change-Id: Icce4333b75190b8036a0a0747bed796b1b709926
Reviewed-on: http://review.couchbase.org/26313
Reviewed-by: Deepkaran Salooja <deepkaran.salooja@globallogic.com>
Tested-by: Deepkaran Salooja <deepkaran.salooja@globallogic.com>