Replace PointToLocal with operator overload in mjCDef.

PiperOrigin-RevId: 609376948
Change-Id: Id69909d06ab48824a9cbe0d5a305e8f8b72a193d

src/user/user_model.cc

@@ -543,7 +543,6 @@ mjCDef* mjCModel::AddDef(string name, int parentid) {
   if (parentid>=0 && parentid<thisid) {
     *def = *defaults[parentid];
     defaults[parentid]->childid.push_back(thisid);
-    def->PointToLocal();
   }
   def->parentid = parentid;
   def->name = name;