freeing the datastore here causes an eventual double free when the new channel
hangs up. We should only free the datastore if we were able to successfully remove
it from the channel we are referencing (i.e. the datastore was not moved).
(closes issue #12359)
Reported by: pguido
git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@114112 65c4cc65-6c06-0410-ace0-fbb531ad65f3