modules/saml/docs/sp.txt: minor fix: ext[] -> $ext[].

git-svn-id: https://simplesamlphp.googlecode.com/svn/trunk@2869 44740490-163a-0410-bde0-09ae8108e29a

modules/saml/docs/sp.txt

@@ -116,7 +116,7 @@ Here we will list some examples for this authentication source.
 
     $dom = new DOMDocument();
     $ce = $dom->createElementNS('http://www.example.com/XFoo', 'xfoo:test', 'Test data!');
-    ext[] = new SAML2_XML_Chunk($ce);
+    $ext[] = new SAML2_XML_Chunk($ce);
 
     $auth = new SimpleSAML_Auth_Simple('default-sp');
     $auth->login(array(