Wrong variable in page_manager_enable_page(), should be $page not $cache

While tracing through page_manager_enable_page() I saw that it was referencing a variable named $cache that had not been declared:

      // We want to re-cache this if it's changed so that status is properly
      // updated on the changed form.
      if (!empty($cache->changed)) {
        page_manager_set_page_cache($cache);
      }

Speaking with merlinofchaos on IRC he believed this should simply have been $page instead of $cache.