Fix [16249]. $typenow is considered empty on edit-tags screens, rather than...

Fix [16249]. $typenow is considered empty on edit-tags screens, rather than displaying the parent post type. Switch to the $post_type global for now, which is set in the terms list table constructor. see #14886.

git-svn-id: https://core.svn.wordpress.org/trunk@19043 1a063a9b-81f0-0310-95a4-ce76da25c4cd