No need to run twentyeleven_url_grabber twice

[duck_]

Just run it once to get the result and if that's false then replace it with the permalink.

Related: #17267

Always best to be explicit about it. I'd suggest this style instead:

if ( false == ( $link_url = twentyeleven_url_grabber() ) ) {
  $link_url = get_permalink();
}

I initially did that but personally found it a bit harder to read, but achieves the same result.

Even better is to run it once and use get_permalink() only as a fallback. empty() catches the false and an empty string.

$link_url = twentyeleven_url_grabber();
if ( empty( $link_url ) )
   $link_url = get_permalink();

In [17917]:

Twenty Eleven: run twentyeleven_url_grabber once in widgets.php, props duck_ -- closes #17279