Avoid duplicate effect state objects in the freelist
Avoid duplicate effect state objects in the freelist

If an unapplied update was superceded, it would be placed in the freelist with
its effect state object intact. This would cause another update with the same
effect state object to be placed into the freelist as well, or worse, cause it
to get deleted while in use when the container had its effect state cleared.

aaronmjacobs/openal-soft,aaronmjacobs/openal-soft