Fix a refcount error introduced by yesterday's OBJ_MULTIPLE commit.

Fix a refcount error introduced by yesterday's OBJ_MULTIPLE commit.

When an object is being unlinked from its container *and* being returned to
the caller, we do not want to decrement the reference count after unlinking
it from the container, as the reference that the container held is what we
are returning to the caller... and if it was the only remaining reference to
the object, that could result in the object being destroyed.

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@225405 65c4cc65-6c06-0410-ace0-fbb531ad65f3