Issue #2080703 by chertzog | mrsinguyen: Remove Unused local variable from...

Issue #2080703 by chertzog | mrsinguyen: Remove Unused local variable  from /core/modules/rdf/rdf.module.

core/modules/rdf/rdf.module

@@ -254,7 +254,6 @@ function rdf_theme() {
 function rdf_preprocess_html(&$variables) {
   // Adds RDF namespace prefix bindings in the form of an RDFa 1.1 prefix
   // attribute inside the html element.
-  $prefixes = array();
   if (!isset($variables['html_attributes']['prefix'])) {
     $variables['html_attributes']['prefix'] = array();
   }