doc PG 17 relnotes: fix pg_stat_statements typo

Reported-by: Masahiko Sawada

Discussion: https://postgr.es/m/CAD21AoB_MR=S_Gh=oeJR4ji0GGY+d8747O-5pYcbMbhGOMtAwQ@mail.gmail.com

Author: Masahiko Sawada

Backpatch-through: master

Author: bmomjian

doc/src/sgml/release-17.sgml

@@ -2722,7 +2722,7 @@ This is useful for testing.
      </itemizedlist>
 
     <sect4 id="release-17-pgstatstatements">
-     <title><link linkend="pgstatstatements"><application>pg_statstatements</application></link></title>
+     <title><link linkend="pgstatstatements"><application>pg_stat_statements</application></link></title>
 
      <itemizedlist>