Automatic merge from submit-queue (batch tested with PRs 48997, 48595, 48898, 48711, 48972)

remove useless code in podautoscaler

**What this PR does / why we need it**:
code optimization,remove some useless code.

**Special notes for your reviewer:**
My first Kubernetes PR，please let me know if anything wrong on this one.

**Release note**:

```release-note
NONE
```