Remove a ?? in the description of Mac OS support.

Doc/inst/inst.tex

@@ -207,7 +207,7 @@ command-line arguments to the setup script:
 \item set the ``Keep stdio window open on termination'' if you're
   interested in seeing the output of the setup script (which is usually
   voluminous and often useful)
-\item (??) when the command-line dialog pops up, enter ``install'' (you
+\item when the command-line dialog pops up, enter ``install'' (you
   can, of course, enter any Distutils command-line as described in this
   document or in the ``Distributing Python Modules'' document: just
   leave of the initial \code{python setup.py} and you'll be fine)