doc: Update benchmark results

From: Alexander Law <exclusion@gmail.com>

doc/src/sgml/pgcrypto.sgml

@@ -407,7 +407,7 @@ gen_salt(type text [, iter_count integer ]) returns text
       <literal>crypt-bf</literal> numbers are taken using a simple program that
       loops over 1000 8-character passwords.  That way I can show the speed
       with different numbers of iterations.  For reference: <literal>john
-      -test</literal> shows 213 loops/sec for <literal>crypt-bf/5</>.
+      -test</literal> shows 13506 loops/sec for <literal>crypt-bf/5</>.
       (The very small
       difference in results is in accordance with the fact that the
       <literal>crypt-bf</literal> implementation in <filename>pgcrypto</>