entrypoint: Avoid random Doxygen block from api.php and opensearch_desc.php

entrypoint: Avoid random Doxygen block from api.php and opensearch_desc.php

These two entry points have themselves partly indexed by Doxygen
in a very strange way where these two comments cause part of an
if-statement to be seen as the name of a local variable.
Probably due to some kind of bad interaction with the
maintenance/mwdoc-filter.php filter applied to the file before
it gets indexed.

Fix it for now by avoiding use of /** blocks for something that
isn't a class, function, class member or documented global var.

Change-Id: I4903069e704c3283e6ec7a39999a489d0117cc71