Doc: clean up pg_relation_check_pages() documentation.

Commit f2b883969 did not get the memo about the new formatting
style for tables documenting built-in functions.  I noticed because
of a PDF build warning about an overwidth table.

doc/src/sgml/func.sgml

@@ -26192,43 +26192,49 @@ SELECT convert_from(pg_read_binary_file('file_in_utf8.txt'), 'UTF8');
 
    <table id="functions-data-sanity-table">
     <title>Data Sanity Functions</title>
-    <tgroup cols="3">
+    <tgroup cols="1">
      <thead>
-      <row><entry>Name</entry> <entry>Return Type</entry> <entry>Description</entry>
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        Function
+       </para>
+       <para>
+        Description
+       </para></entry>
       </row>
      </thead>
 
      <tbody>
       <row>
-       <entry>
+       <entry role="func_table_entry"><para role="func_signature">
-        <literal><function>pg_relation_check_pages(<parameter>relation</parameter> <type>regclass</type> [, <parameter>fork</parameter> <type>text</type> <literal>DEFAULT</literal> <literal>NULL</literal> ])</function></literal>
-       </entry>
-       <entry><type>setof record</type></entry>
-       <entry>Check the pages of a relation.
-       </entry>
-      </row>
-     </tbody>
-    </tgroup>
-   </table>
-
         <indexterm>
          <primary>pg_relation_check_pages</primary>
         </indexterm>
-   <para id="functions-check-relation-note" xreflabel="pg_relation_check_pages">
+        <function>pg_relation_check_pages</function> ( <parameter>relation</parameter> <type>regclass</type> [, <parameter>fork</parameter> <type>text</type> ] )
-    <function>pg_relation_check_pages</function> iterates over all blocks of a
+        <returnvalue>setof record</returnvalue>
-    given relation and verifies if they are in a state where they can safely
+        ( <parameter>path</parameter> <type>text</type>,
-    be loaded into the shared buffers. If defined,
+        <parameter>failed_block_num</parameter> <type>bigint</type> )
-    <replaceable>fork</replaceable> specifies that only the pages of the given
+       </para>
-    fork are to be verified. Fork can be <literal>'main'</literal> for the
+       <para>
-    main data fork, <literal>'fsm'</literal> for the free space map,
+        Checks the pages of the specified relation to see if they are valid
-    <literal>'vm'</literal> for the visibility map, or
+        enough to safely be loaded into the server's shared buffers.  If
-    <literal>'init'</literal> for the initialization fork.  The default of
+        given, <parameter>fork</parameter> specifies that only the pages of
-    <literal>NULL</literal> means that all the forks of the relation are
+        the given fork are to be verified.  <parameter>fork</parameter> can
-    checked. The function returns a list of blocks that are considered as
+        be <literal>main</literal> for the main data
-    corrupted with the path of the related file. Use of this function is
+        fork, <literal>fsm</literal> for the free space
-    restricted to superusers by default but access may be granted to others
+        map, <literal>vm</literal> for the visibility map,
+        or <literal>init</literal> for the initialization fork.  The
+        default of <literal>NULL</literal> means that all forks of the
+        relation should be checked.  The function returns a list of block
+        numbers that appear corrupted along with the path names of their
+        files.  Use of this function is restricted to superusers by
+        default, but access may be granted to others
         using <command>GRANT</command>.
-   </para>
+       </para></entry>
+      </row>
+     </tbody>
+    </tgroup>
+   </table>
 
   </sect2>