elm/scroller: return immediately from updating focused scroll region without content

Summary:
there is nothing to update here if the scroller has no content to update

@fix
Depends on D9000

Reviewers: devilhorns

Reviewed By: devilhorns

Subscribers: cedric, #reviewers, #committers

Tags: #efl

Differential Revision: https://phab.enlightenment.org/D9001

src/lib/elementary/elm_scroller.c

@@ -879,6 +879,8 @@ _focused_element(void *data, const Efl_Event *event)
    pd = efl_data_scope_get(obj, ELM_INTERFACE_SCROLLABLE_MIXIN);
 
    if (!focus) return;
+   /* no scroller content set */
+   if (!pd->pan_obj) return;
 
    geom = efl_ui_focus_object_focus_geometry_get(focus);
    pos = efl_gfx_entity_position_get(obj);