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>.
scheduler: clean up and simplify equivalence cache locking
**What this PR does / why we need it**:
This is a cleanup of the locking code for equivalence cache. There is no change to the current logic or locking. This PR has a couple of implications, though.
1. It deletes (unreachable) code that could have been used to cache predicate results that consider nominated pods.
2. Callers should no longer lock/unlock the eCache manually, so coordinating that lock with other synchronization is restricted.
**Special notes for your reviewer**:
**Release note**:
<!-- Write your release note:
1. Enter your extended release note in the below block. If the PR requires additional action from users switching to the new release, include the string "**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes #
**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes #
action required".
2. If no release note is required, just write "NONE".
-->
```release-note
NONE
```
/sig scheduling
/kind cleanup
12a6236148