Tooltip: reset content delete callback directly after invocation

The deletion of the content object can lead to invoke the delete
callback twice.

@fix

legacy/elementary/src/lib/els_tooltip.c

@@ -792,11 +792,10 @@ static void
 _elm_tooltip_data_clean(Elm_Tooltip *tt)
 {
    if (tt->del_cb) tt->del_cb((void *)tt->data, tt->owner, NULL);
+   tt->del_cb = NULL;
+   tt->data = NULL;
 
    _elm_tooltip_content_del(tt);
-
-   tt->data = NULL;
-   tt->del_cb = NULL;
 }
 
 EAPI void