kyaml: rename annotations and fix linting

kyaml/yaml/walk/visitor.go

@@ -1,16 +1,5 @@
-// Copyright 2019 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
 
 package walk
 
@@ -34,5 +23,5 @@ type Visitor interface {
 	VisitList(nodes Sources, kind ListKind) (*yaml.RNode, error)
 }
 
-// NoOp is returned if GrepFilter should do nothing after calling Set
-var ClearNode *yaml.RNode = nil
+// ClearNode is returned if GrepFilter should do nothing after calling Set
+var ClearNode *yaml.RNode