CBQE-0: fix get_bucket_stats_for_node when status false

Change-Id: I684aa1a817c1a5f09d506bec7161f70e84dc011f
Reviewed-on: http://review.couchbase.org/39755
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>