cmd: kubectl: remove golint_failures entry

`.golint_failures` currently has an entry for `cmd/kubectl/app`. We can lint this package and remove
the entry. There is only one `golint` warning; comment on exported function Run should be of the
form "Run ..."

Fix documentation comment and remove `cmd/kubectl/app` from `.golint_failures`.

cmd/kubectl/app/kubectl.go

@@ -31,6 +31,8 @@ import (
 WARNING: this logic is duplicated, with minor changes, in cmd/hyperkube/kubectl.go
 Any salient changes here will need to be manually reflected in that file.
 */
+
+// Run runs the kubectl program (creates and executes a new cobra command).
 func Run() error {
 	logs.InitLogs()
 	defer logs.FlushLogs()

hack/.golint_failures

@@ -9,7 +9,6 @@ cmd/kube-proxy/app
 cmd/kubeadm/app
 cmd/kubeadm/app/apis/kubeadm
 cmd/kubeadm/app/apis/kubeadm/v1alpha1
-cmd/kubectl/app
 cmd/kubelet/app
 cmd/kubelet/app/options
 cmd/kubemark