efl_ui_spin_button: remove needless focus_set

Summary:
because _entry_show_cb callback call focus_set function,
efl_ui_focus_manager_focus_set is unnecessary.
also, this fixes focus error message.

Test Plan:
1. elementary_test -to Efl.Ui.Spin.Button
2. click the entry.

Reviewers: CHAN, Jaehyun_Cho, bu5hm4n

Reviewed By: CHAN

Subscribers: cedric, jpeg

Differential Revision: https://phab.enlightenment.org/D5641

src/lib/elementary/efl_ui_spin_button.c

@@ -388,8 +388,6 @@ _toggle_entry(Evas_Object *obj)
 
            efl_ui_focus_composition_elements_set(obj, items);
         }
-
-        efl_ui_focus_manager_focus_set(efl_ui_focus_user_focus_manager_get(obj), sd->ent);
      }
 }