Merge pull request #31944 from m1093782566/m109-master-fix-found
Automatic merge from submit-queue
[Pet Set] Clean up code
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**What this PR does / why we need it**:
Clean code of petset, from:
```
func (p *apiServerPetClient) getPVC(pvcName, pvcNamespace string) (*api.PersistentVolumeClaim, bool, error)
```
to:
```
func (p *apiServerPetClient) getPVC(pvcName, pvcNamespace string) (*api.PersistentVolumeClaim, error)
```
I think the 2nd(bool type) return value of [getPVC](https://github.com/kubernetes/kubernetes/blob/master/pkg/controller/petset/pet.go#L228) is unnecessary, as the caller can be responsible for checking the error type and tell if it exists via the [error type](https://github.com/kubernetes/kubernetes/blob/master/pkg/controller/petset/pet.go#L231-L233).
So, I remove the 2nd return value of `getPVC()`.
The benefit of this change is that we can simplify the code of `getPVC()` while don't increase the caller's code.