Index: wp-includes/rest-api/class-wp-rest-server.php
===================================================================
--- wp-includes/rest-api/class-wp-rest-server.php	(revision 56098)
+++ wp-includes/rest-api/class-wp-rest-server.php	(working copy)
@@ -1079,7 +1079,6 @@
 
 			foreach ( $handlers as $handler ) {
 				$callback = $handler['callback'];
-				$response = null;
 
 				// Fallback to GET method if no HEAD method is registered.
 				$checked_method = $method;