The previous code left one error path where the module would be unref'd twice
instead of once.  It was done once in the error handling block, and again inside
of datastore destruction.

Now the module ref is only released in the datastore destructor and only acquired
when the datastore has been successfully allocated.



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@412280 65c4cc65-6c06-0410-ace0-fbb531ad65f3