Fix markup that doesn't work in HISTORY generation.

doc/src/sgml/release.sgml

-<!-- $PostgreSQL: pgsql/doc/src/sgml/release.sgml,v 1.539 2007/11/15 20:10:32 momjian Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/release.sgml,v 1.540 2007/11/16 06:28:07 tgl Exp $ -->
 <!--
 Typical markup:
@@ -2214,7 +2214,7 @@ substr(current_date::text, 1, 1);
      <listitem>
       <para>
        Add <link linkend="acronyms">acronym</link> and <link
-       linkend="creating-cluster-nfs"><acronym>NFS</></> documentation
+       linkend="creating-cluster-nfs">NFS</link> documentation
        sections (Bruce)
       </para>
      </listitem>