Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
generated code should pass go vet for go1.10
**What this PR does / why we need it**:
Update code generator and the code it generates to pass `go vet`.
go1.10 runs `go vet` whenever `go test` is run. Because of this, generated code for CRDs needs to pass `go vet`.
**Release note**:
```release-note
Code generated for CRDs now passes `go vet`.
```
Kubernetes-commit: 5dde701b876d1d0915314c3ed146e986c4327f7e
Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
sample-controller: add example CRD controller
**What this PR does / why we need it**:
Adds a sample-controller example repository
fixes#52752
**Special notes for your reviewer**:
This is currently based on the sttts:sttts-codegen-scripts branch and should not be merged until that is (ref https://github.com/kubernetes/kubernetes/pull/52186)
**Release note**:
```
Add sample-controller repository
```
/cc @sttts @nikhita @colemickens
Kubernetes-commit: 9a7800f7d2efb88b397674672ac56f898826cf7c