doc: Consistently use = sign in long options synopses

This was already the predominant form in man pages and help output.

doc/src/sgml/ref/clusterdb.sgml

@@ -316,7 +316,7 @@ PostgreSQL documentation
     <literal>foo</literal> in a database named
     <literal>xyzzy</literal>:
 <screen>
-<prompt>$ </prompt><userinput>clusterdb --table foo xyzzy</userinput>
+<prompt>$ </prompt><userinput>clusterdb --table=foo xyzzy</userinput>
 </screen></para>
 
  </refsect1>

doc/src/sgml/ref/pg_ctl-ref.sgml

@@ -263,7 +263,7 @@ PostgreSQL documentation
 
      <varlistentry>
       <term><option>-D <replaceable class="parameter">datadir</replaceable></option></term>
-      <term><option>--pgdata <replaceable class="parameter">datadir</replaceable></option></term>
+      <term><option>--pgdata=<replaceable class="parameter">datadir</replaceable></option></term>
       <listitem>
        <para>
         Specifies the file system location of the database configuration files.  If
@@ -275,7 +275,7 @@ PostgreSQL documentation
 
      <varlistentry>
       <term><option>-l <replaceable class="parameter">filename</replaceable></option></term>
-      <term><option>--log <replaceable class="parameter">filename</replaceable></option></term>
+      <term><option>--log=<replaceable class="parameter">filename</replaceable></option></term>
       <listitem>
        <para>
         Append the server log output to
@@ -288,7 +288,7 @@ PostgreSQL documentation
 
      <varlistentry>
       <term><option>-m <replaceable class="parameter">mode</replaceable></option></term>
-      <term><option>--mode <replaceable class="parameter">mode</replaceable></option></term>
+      <term><option>--mode=<replaceable class="parameter">mode</replaceable></option></term>
       <listitem>
        <para>
         Specifies the shutdown mode.  <replaceable>mode</replaceable>

doc/src/sgml/ref/pgupgrade.sgml

@@ -558,7 +558,7 @@ rsync --archive --delete --hard-links --size-only old_pgdata new_pgdata remote_d
      run using:
 
 <programlisting>
-psql --username postgres --file script.sql postgres
+psql --username=postgres --file=script.sql postgres
 </programlisting>
 
      The scripts can be run in any order and can be deleted once they have

doc/src/sgml/ref/reindexdb.sgml

@@ -396,7 +396,7 @@ PostgreSQL documentation
     To reindex the table <literal>foo</literal> and the index
     <literal>bar</literal> in a database named <literal>abcd</literal>:
 <screen>
-<prompt>$ </prompt><userinput>reindexdb --table foo --index bar abcd</userinput>
+<prompt>$ </prompt><userinput>reindexdb --table=foo --index=bar abcd</userinput>
 </screen></para>
 
  </refsect1>

doc/src/sgml/ref/vacuumdb.sgml

@@ -430,7 +430,7 @@ PostgreSQL documentation
     <literal>xyzzy</literal>, and analyze a single column
     <literal>bar</literal> of the table for the optimizer:
 <screen>
-<prompt>$ </prompt><userinput>vacuumdb --analyze --verbose --table 'foo(bar)' xyzzy</userinput>
+<prompt>$ </prompt><userinput>vacuumdb --analyze --verbose --table='foo(bar)' xyzzy</userinput>
 </screen></para>
 
  </refsect1>