Log an error when we didn't move enough buckets.
Log an error when we didn't move enough buckets.

Change-Id: I84e6cc0055aee339c866add813420ae71e9a3287
Reviewed-on: http://review.membase.org/4223
Reviewed-by: Steve Yen <ef850f73f7832052d3c6d9b5ddd3a1716d9a57f1@gmail.com>
Tested-by: Steve Yen <ef850f73f7832052d3c6d9b5ddd3a1716d9a57f1@gmail.com>

zbase/vbucketmigrator,membase/vbucketmigrator,membase/vbucketmigrator,membase/vbucketmigrator,zbase/vbucketmigrator,zbase/vbucketmigrator,membase/vbucketmigrator,zbase/vbucketmigrator