removed incorrect destructor (to prevent deleting item by recursion instead of...

removed incorrect destructor (to prevent deleting item by recursion instead of by list scanning in case of chained OR or AND)

sql/item_cmpfunc.h

@@ -534,7 +534,6 @@ class Item_cond :public Item_bool_func
   Item_cond() : Item_bool_func() { const_item_cache=0; }
   Item_cond(Item *i1,Item *i2) :Item_bool_func()
     { list.push_back(i1); list.push_back(i2); }
-  ~Item_cond() { list.delete_elements(); }
   bool add(Item *item) { return list.push_back(item); }
   bool fix_fields(THD *,struct st_table_list *);