[General] Fix issues with MechanicsHelper::getItemPtrFromStore()

apps/openmw/mwmp/MechanicsHelper.cpp

@@ -374,4 +374,6 @@ MWWorld::Ptr MechanicsHelper::getItemPtrFromStore(const mwmp::Item& item, MWWorl
             return *storeIterator;
         }
     }
+
+    return 0;
 }

apps/openmw/mwmp/processors/player/ProcessorPlayerItemUse.hpp

@@ -35,7 +35,7 @@ namespace mwmp
                 MWWorld::Ptr &playerPtr = MWBase::Environment::get().getWorld()->getPlayerPtr();
                 MWWorld::InventoryStore &inventoryStore = playerPtr.getClass().getInventoryStore(playerPtr);
 
-                MWWorld::Ptr &itemPtr = MechanicsHelper::getItemPtrFromStore(player->usedItem, inventoryStore);
+                MWWorld::Ptr itemPtr = MechanicsHelper::getItemPtrFromStore(player->usedItem, inventoryStore);
                 MWBase::Environment::get().getWindowManager()->getInventoryWindow()->useItem(itemPtr);
             }
         }