No need to close the open checkpoint id, happens automatically

Change-Id: I5b27c26c5858c47d2a5bab29e68123ff1302833c
Reviewed-on: http://review.couchbase.org/42929
Reviewed-by: Chiyoung Seo <chiyoung@couchbase.com>
Tested-by: Michael Wiederhold <mike@couchbase.com>