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 duplicated code in aws ebs unit test

**What this PR does / why we need it**:

This code is duplicated with the above(see [here](https://github.com/kubernetes/kubernetes/blob/b3ec8295be792cf752873f3781369204d3b05ea0/pkg/volume/aws_ebs/aws_ebs_test.go#L141) and [here](https://github.com/kubernetes/kubernetes/blob/b3ec8295be792cf752873f3781369204d3b05ea0/pkg/volume/aws_ebs/aws_ebs_test.go#L148)), so we can just remove the second one.

**Release note**:

```release-note
NONE
```

/sig storage