Revert "ecore_x: remove dead code."

This reverts commit 7303fcee4d.

acutally the code was intended for compile warning.

src/lib/ecore_x/xlib/ecore_x_screensaver.c

@@ -168,6 +168,7 @@ ecore_x_screensaver_event_listen_set(Eina_Bool on)
      XScreenSaverSelectInput(_ecore_x_disp, root, 0);
 #else
    return;
+   on = EINA_FALSE;
 #endif /* ifdef ECORE_XSS */
 }