GlobalFunctions: use a closure instead of polluting global namespace

Change-Id: Ia587008de75a8bde90ad45d4932284f0b6401845

includes/GlobalFunctions.php

@@ -866,20 +866,13 @@ function wfParseUrl( $url ) {
 function wfExpandIRI( $url ) {
 	return preg_replace_callback(
 		'/((?:%[89A-F][0-9A-F])+)/i',
-		'wfExpandIRI_callback',
+		function ( array $matches ) {
+			return urldecode( $matches[1] );
+		},
 		wfExpandUrl( $url )
 	);
 }
 
-/**
- * Private callback for wfExpandIRI
- * @param array $matches
- * @return string
- */
-function wfExpandIRI_callback( $matches ) {
-	return urldecode( $matches[1] );
-}
-
 /**
  * Make URL indexes, appropriate for the el_index field of externallinks.
  *