SCI sfx: fix song iterators from not getting freed
|Reported by:||SF/lwalkera||Owned by:||bluegr|
Fix iterators from not getting freed when there's only one song left playing. Prevents the flock of seagulls from following you around going back and forth from the beach to the tree at the very beginning of KQ6. :)
Ticket imported from: #2891230. Ticket imported from: patches/1209.