fixed missing error 'next' callback

lib/walk.js

@@ -51,7 +51,7 @@
           });
         }).then(function () {
           if (fnodeGroups.errors.length) {
-            emitter.emit('errors', curpath, fnodeGroups.errors);
+            emitter.emit('errors', curpath, fnodeGroups.errors, noop);
           }
           TypeEmitter.emitNodeTypeGroups(emitter, curpath, fnodeGroups, function () {
             var dirs = [];