Remove compile warning
Remove compile warning

variable ‘written’ set but not used [-Wunused-but-set-variable]

Change-Id: I3916131e4fad6a7a96c9e46579056e2352496e79
Reviewed-on: http://review.couchbase.org/42825
Reviewed-by: Dave Rigby <a09264da4832c7ff1d3bf1608a19f4b870f93750@couchbase.com>
Tested-by: Trond Norbye <60edd2ef23891a753f231b0c6f161dc634079a93@gmail.com>

membase/moxi,membase/moxi,couchbase/moxi,membase/moxi,couchbase/moxi,couchbase/moxi,membase/moxi,couchbase/moxi,membase/moxi,membase/moxi,couchbase/moxi,couchbase/moxi