Revert "Fix race conidtion when deleting vbuckets"

This reverts commit ca2370576f7387416f3ae6b26f2b2b13539abdd9.

Change-Id: Ie3e376d6a1ddf36c1bfdb97ef6415d2561ea6105
Reviewed-on: http://review.couchbase.org/36425
Tested-by: abhinav dangeti <abhinav@couchbase.com>
Reviewed-by: Chiyoung Seo <chiyoung@couchbase.com>