examples.xml Amend the case in the class name (php#4794)

Author: mmalferov

reference/simplexml/examples.xml

@@ -466,7 +466,7 @@ echo count($movies->xpath("//movie")) . "\n";
    iterate over the errors.
   </para>
   <para>
-   The <classname>libXMLError</classname> object, returned by
+   The <classname>LibXMLError</classname> object, returned by
    <function>libxml_get_errors</function>, contains several properties
    including the <link linkend="libxmlerror.props.message">message</link>,
    <link linkend="libxmlerror.props.line">line</link> and