py: Fix "TypeError: 'iterator' object is not iterable", doh.
diff --git a/py/objset.c b/py/objset.c
index 2cabf6c..439c6e9 100644
--- a/py/objset.c
+++ b/py/objset.c
@@ -72,6 +72,7 @@
 const mp_obj_type_t mp_type_set_it = {
     { &mp_type_type },
     .name = MP_QSTR_iterator,
+    .getiter = mp_identity,
     .iternext = set_it_iternext,
 };