All languages HTML in label not rendered

Problem/Motivation

If there is a field that cannot be translated, in a translatable content type, then Drupal adds a span-element with label "(all languages)" in to the field label.

In the Entity Reference tree -widget the possible HTML is not handled, resulting the HTML being printed as text.

Steps to reproduce

1. Create a translatable content type
2. Create an entity reference field that is not translatable
3. Set the field to use the Entity reference tree -widget, add custom label in the widget options
4. View the field in node edit or add. See HTML printed in the label