Fix "part has no parents" warning message caused by nodes being destroyed in the incorrect order

apps/openmw/mwrender/creatureanimation.cpp

@@ -75,6 +75,7 @@ void CreatureWeaponAnimation::showCarriedLeft(bool show)
 
 void CreatureWeaponAnimation::updateParts()
 {
+    mAmmunition.reset();
     mWeapon.reset();
     mShield.reset();
 

apps/openmw/mwrender/npcanimation.cpp

@@ -567,6 +567,7 @@ void NpcAnimation::updateParts()
     static const size_t slotlistsize = sizeof(slotlist)/sizeof(slotlist[0]);
 
     bool wasArrowAttached = (mAmmunition.get() != NULL);
+    mAmmunition.reset();
 
     MWWorld::InventoryStore& inv = mPtr.getClass().getInventoryStore(mPtr);
     for(size_t i = 0;i < slotlistsize && mViewMode != VM_HeadOnly;i++)