cxx: Initialize _list and _node with nullptr

Fixes CID 1409576 pointing that _node was unitialized.

Reviewed-by: Stefan Schmidt <stefan@datenfreihafen.org>
Reviewed-by: Felipe Magno de Almeida <felipe@expertisesolutions.com.br>
Differential Revision: https://phab.enlightenment.org/D11770

src/bindings/cxx/eina_cxx/eina_ptrlist.hh

@@ -53,7 +53,7 @@ struct _ptr_list_iterator_base
   typedef std::ptrdiff_t difference_type;
   typedef std::bidirectional_iterator_tag iterator_category;
 
-  _ptr_list_iterator_base() : _list(0) {}
+  _ptr_list_iterator_base() : _list(nullptr), _node(nullptr) {}
   _ptr_list_iterator_base(Eina_List* list, Eina_List* node)
     : _list(list), _node(node)
   {}