Finish rename of PQtraceSetFlags() to PQsetTraceFlags().

Jie Zhang

Discussion: https://postgr.es/m/TYWPR01MB767844835390EDD8DB276D75F90A9@TYWPR01MB7678.jpnprd01.prod.outlook.com

doc/src/sgml/libpq.sgml

@@ -6535,7 +6535,7 @@ void PQtrace(PGconn *conn, FILE *stream);
    </varlistentry>
 
    <varlistentry id="libpq-PQsetTraceFlags">
-    <term><function>PQsetTraceFlags</function><indexterm><primary>PQtraceSetFlags</primary></indexterm></term>
+    <term><function>PQsetTraceFlags</function><indexterm><primary>PQsetTraceFlags</primary></indexterm></term>
 
     <listitem>
      <para>