Modification: revise some errors about golint in some packages
Modification: revise some errors about golint in some packages

1. pkg/client
2. staging/src/k8s.io/apiserver/pkg/admission/plugin/webhook/testing

Related to: https://github.com/kubernetes/kubernetes/issues/68026

Kubernetes-commit: 1fbb8b20e20616e1a1e957c01b1bb595c7703433

kubernetes/apiserver,kubernetes/apiserver