[LTTP] Fix a bug in Triforce Pieces Mode: Extra

When triforce_pieces_mode is set to "extra", the number of Triforce pieces in the pool should be equal to the number required plus the number extra. The number available was being used in this calculation, instead of the number required.

worlds/alttp/ItemPool.py

@@ -682,7 +682,7 @@ def place_item(loc, item):
     if 'triforce_hunt' in goal:
 
         if world.triforce_pieces_mode[player].value == TriforcePiecesMode.option_extra:
-            treasure_hunt_total = (world.triforce_pieces_available[player].value
+            treasure_hunt_total = (world.triforce_pieces_required[player].value
                                    + world.triforce_pieces_extra[player].value)
         elif world.triforce_pieces_mode[player].value == TriforcePiecesMode.option_percentage:
             percentage = float(world.triforce_pieces_percentage[player].value) / 100