qom/object: fix iterating properties over a class

object_class_property_iter_init() starts from the given class, so the
next class should continue with the parent class.
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>

qom/object.c

@@ -1115,7 +1115,7 @@ void object_class_property_iter_init(ObjectPropertyIterator *iter,
                                      ObjectClass *klass)
 {
     g_hash_table_iter_init(&iter->iter, klass->properties);
-    iter->nextclass = klass;
+    iter->nextclass = object_class_get_parent(klass);
 }
 
 ObjectProperty *object_class_property_find(ObjectClass *klass, const char *name,