errorexception.xml: remove the extra dot cahr; combed the example code (#3539)

Author: mmalferov

language/predefined/errorexception.xml

@@ -77,26 +77,30 @@
    &reftitle.examples;
    <para>
     <example xml:id="errorexception.example.error-handler"><!-- {{{ -->
-     <title>Use <function>set_error_handler</function> to change error messages into ErrorException.</title>
+     <title>Use <function>set_error_handler</function> to change error messages into ErrorException</title>
      <programlisting role="php">
  <![CDATA[
 <?php
+
 set_error_handler(function (int $errno, string $errstr, string $errfile, int $errline) {
     if (!(error_reporting() & $errno)) {
         // This error code is not included in error_reporting.
         return;
     }
+
     if ($errno === E_DEPRECATED || $errno === E_USER_DEPRECATED) {
         // Do not throw an Exception for deprecation warnings as new or unexpected
         // deprecations would break the application.
         return;
     }
+
     throw new \ErrorException($errstr, 0, $errno, $errfile, $errline);
 });
 
 // Unserializing broken data triggers a warning which will be turned into an
 // ErrorException by the error handler.
 unserialize('broken data');
+
 ?>
 ]]>
      </programlisting>