elm_gengrid: do not zero item cache if object is not finalized

this is a no-op case which causes unnecessary errors

Signed-off-by: Mike Blumenkrantz <zmike@osg.samsung.com>

src/lib/elementary/elm_gengrid.c

@@ -3552,7 +3552,8 @@ _mirrored_set(Evas_Object *obj,
 
    ELM_GENGRID_DATA_GET(obj, sd);
 
-   _item_cache_zero(sd);
+   if (efl_finalized_get(sd->obj))
+     _item_cache_zero(sd);
    efl_ui_mirrored_set(efl_super(obj, MY_CLASS), rtl);
 
    if (!sd->items) return;