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>.
remove some unused functions in validation.go
**What this PR does / why we need it**:
remove some unused functions in validation.go
**Special notes for your reviewer**:
**Release note**:
```release-note
NONE
```
c43fd9554e