Eliminate use of extract() in get_media_item().

To test, fire open the old media in the console: `tb_show('Old Media is Weird', 'media-upload.php?type=image&TB_iframe=true&post_id=0');`	
	
See #22400.


git-svn-id: https://develop.svn.wordpress.org/trunk@28407 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/bookmark-template.php

@@ -241,7 +241,7 @@ function wp_list_bookmarks( $args = '' ) {
 		}
 	}
 
-	if ( $categorize ) {
+	if ( $r['categorize'] ) {
 		// Split the bookmarks into ul's for each category
 		foreach ( (array) $cats as $cat ) {
 			$params = array_merge( $r, array( 'category' => $cat->term_id ) );