py: simplify __next__ method for generators.
diff --git a/py/runtime.c b/py/runtime.c
index a3d11f3..7d1357a 100644
--- a/py/runtime.c
+++ b/py/runtime.c
@@ -772,7 +772,7 @@
 void rt_load_method(mp_obj_t base, qstr attr, mp_obj_t *dest) {
     DEBUG_OP_printf("load method %s\n", qstr_str(attr));
     if (MP_OBJ_IS_TYPE(base, &gen_instance_type) && attr == rt_q___next__) {
-        dest[1] = (mp_obj_t)&mp_obj_gen_instance_next_obj;
+        dest[1] = (mp_obj_t)&mp_builtin_next_obj;
         dest[0] = base;
         return;
     } else if (MP_OBJ_IS_TYPE(base, &instance_type)) {