Fix golint verify error

[CaoShuFeng]

I don't know why CI pass the hack/verify-golint.sh test.
But in my environment I get this:

staging/src/k8s.io/client-go/util/workqueue/queue_test.go is in package workqueue_test, not workqueue
Errors from golint:
test/integration/apiserver/apiserver_test.go:102:13: should omit type string from declaration of var cascDel; it will be inferred from the right-hand side
Please fix the above errors. You can test via "golint" and commit the result.
!!! Error in hack/verify-golint.sh:98
Error in hack/verify-golint.sh:98. 'false' exited with status 1
Call stack:
1: hack/verify-golint.sh:98 main(...)
Exiting with status 1

This change fix this err in my environment.
Release note:

[k8s-reviewable]

This change is 

[k8s-ci-robot]

Hi @CaoShuFeng. Thanks for your PR.

I'm waiting for a kubernetes member to verify that this patch is reasonable to test. If it is, they should reply with @k8s-bot ok to test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository. I understand the commands that are listed here.

[cblecker]

@k8s-bot ok to test

[fejta]

Would you prefer this?

cascDel := `foo`

[CaoShuFeng]

I tried this way, but I found that golang doesn't support it.
Short variable declarations may appear only inside functions.
Reference:
https://golang.org/ref/spec#Short_variable_declarations
Thanks

[mikedanese]

/lgtm

[k8s-github-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: CaoShuFeng, mikedanese

Needs approval from an approver in each of these OWNERS Files:

• test/OWNERS [mikedanese]

You can indicate your approval by writing /approve in a comment
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[k8s-github-robot]

Automatic merge from submit-queue