elm/hoversel: force calc on internal hover object during activate

hoversel can't accurately determine its location until the hover object
has been calculated, so this needs to always happen before the hoversel
is made visible in order to correctly position the hover

fix T8642

Reviewed-by: Stefan Schmidt <stefan@datenfreihafen.org>
Reviewed-by: Marcel Hollerbach <mail@marcel-hollerbach.de>
Differential Revision: https://phab.enlightenment.org/D11646

src/lib/elementary/elc_hoversel.c

@@ -523,6 +523,8 @@ _activate(Evas_Object *obj)
    if (_elm_config->access_mode) _access_widget_item_register(sd);
 
    efl_event_callback_legacy_call(obj, ELM_HOVERSEL_EVENT_EXPANDED, NULL);
+   efl_canvas_group_calculate(sd->hover);
+   _sizing_eval(obj);
    evas_object_show(sd->hover);
 }