Here is the line in feed.php it says has the syntax error:
echo apply_filters(‘atom_enclosure’, ‘<link href=”‘%20.%20trim(htmlspecialchars($enclosure%5b0%5d))%20.%20′” rel=”enclosure” length=”‘ . trim($enclosure[1]) . ‘” type=”‘ . trim($enclosure[2]) . ‘” />’ . “\n”);