Follows-up T253938 / https://gerrit.wikimedia.org/r/615321, which caused the function to no longer work when called by reference, or as callback, or by a variable, or in a different utility class.
Reported at https://en.wikipedia.org/wiki/Wikipedia:Village_pump_(technical)#Scripts_do_not_show_up.
Users are finding that the global function addPortletLink no longer works, and is causing other code in those gadgets and scripts to be cancelled as a result as well (the global is a mw.log.deprecate alias to mw.util.addPortletLink).
For example:
var add = mw.util.addPortletLink; add(); // throws function init(add) { add(); // throws } init(mw.util.addPortletLink); var skinUtils = { addLink: mw.util.addPortletLink } skinUtils.addLink(); // throws