Doc: Fix punctuation errors

Author: 斉藤登 <noborusai@gmail.com>
Reviewed-by: David G. Johnston <david.g.johnston@gmail.com>
Discussion: https://postgr.es/m/CAAM3qnL6i-BSu5rB2+KiHLjMCOXiQEiPMBvEj7F1CgUzZMooLA@mail.gmail.com
Backpatch-through: 13

doc/src/sgml/config.sgml

@@ -7489,7 +7489,7 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv;
         various purposes.  The cluster name appears in the process title for
         all server processes in this cluster.  Moreover, it is the default
         application name for a standby connection (see <xref
-        linkend="guc-synchronous-standby-names"/>.)
+        linkend="guc-synchronous-standby-names"/>).
        </para>
 
        <para>

doc/src/sgml/libpq.sgml

@@ -4756,7 +4756,7 @@ PGresult *PQgetResult(PGconn *conn);
        <literal>PGRES_PIPELINE_SYNC</literal> will be returned.
        The result of the next query after the synchronization point follows
        immediately (that is, no null pointer is returned after
-       the synchronization point.)
+       the synchronization point).
       </para>
 
       <note>