kubeadm: fix deepcopy generation due to missing opt-in tag

cmd/kubeadm/app/phases/etcd/spec/doc.go

+/*
+Copyright 2017 The Kubernetes Authors.
+
+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.
+*/
+
+// +k8s:deepcopy-gen=package
+
+package spec

hack/.golint_failures

@@ -7,6 +7,7 @@ cmd/kube-proxy/app
 cmd/kubeadm/app
 cmd/kubeadm/app/apis/kubeadm
 cmd/kubeadm/app/apis/kubeadm/v1alpha1
+cmd/kubeadm/app/phases/etcd/spec
 cmd/kubelet/app
 cmd/kubelet/app/options
 cmd/kubemark