[wwwdocs] Update reference to MMIX

[Gerald Pfeifer]

On Sat, 9 Sep 2017, Tim Song wrote:
>> +   href="http://www-cs-faculty.stanford.edu/~knuth/mmix.htmll">MMIX
> This one has one too many l's.

You've got sharp eyes, Tim!

Thanks for catching this; fixed thusly.

Gerald

Index: readings.html
===================================================================
RCS file: /cvs/gcc/wwwdocs/htdocs/readings.html,v
retrieving revision 1.280
diff -u -r1.280 readings.html
--- readings.html	9 Sep 2017 06:33:54 -0000	1.280
+++ readings.html	9 Sep 2017 14:00:45 -0000
@@ -209,7 +209,7 @@
    <a href="http://www-cs-faculty.stanford.edu/~uno/taocp.html">The Art
    of Computer Programming</a> (ISBN 0-201-89683-4).
    <br />The <a
-   href="http://www-cs-faculty.stanford.edu/~knuth/mmix.htmll">MMIX
+   href="http://www-cs-faculty.stanford.edu/~knuth/mmix.html">MMIX
    page</a> has more information about MMIX.  Knuth also wrote a
    <a href="http://www-cs-faculty.stanford.edu/~knuth/mmixware.html">book
    specifically about MMIX</a> (MMIXware, ISBN 3-540-66938-8).