Revert "efl_ui_layout: check part existence in text_set"

This reverts commit 649433560b.

This patch is reverted because this patch breaks the backward
compatibility.
Please check Popup in elementary_test.

src/lib/elementary/efl_ui_layout.c

@@ -2764,7 +2764,6 @@ elm_layout_text_set(Eo *obj, const char *part, const char *text)
    else if (!_elm_layout_part_aliasing_eval(obj, &part, EINA_TRUE))
      return EINA_FALSE;
 
-   if (!efl_layout_group_part_exist_get(obj, part)) return EINA_FALSE;
    efl_text_set(efl_part(obj, part), text);
    return EINA_TRUE;
 }