Fix incorrect link in v10 release notes.

As noted by M. Justin.

Also, to keep the HEAD and REL_10 versions of release-10.sgml in sync,
back-patch the effects of c29c57890 on that file.  We have a bigger
problem there though :-(

Discussion: https://postgr.es/m/CALtA7pmsQyTTD3fC2rmfUWgfivv5sCJJ84PHY0F_5t_SRc07Qg@mail.gmail.com
Discussion: https://postgr.es/m/6d137bd0-eef6-1d91-d9b8-1a5e9195a899@2ndquadrant.com

doc/src/sgml/release-10.sgml

@@ -1982,7 +1982,7 @@
 -->
       <para>
        Allow <link
-       linkend="functions-formatting-table"><function>make_date()</function></link>
+       linkend="functions-datetime-table"><function>make_date()</function></link>
        to interpret negative years as <acronym>BC</acronym> years (&Aacute;lvaro
        Herrera)
       </para>
@@ -1993,7 +1993,9 @@
 2016-09-28 [d3cd36a13] Make to_timestamp() and to_date() range-check fields of
 -->
       <para>
-       Make <function>to_timestamp()</function> and <function>to_date()</function> reject
+       Make <link
+       linkend="functions-formatting-table"><function>to_timestamp()</function></link>
+       and <function>to_date()</function> reject
        out-of-range input fields (Artur Zakirov)
       </para>