When cert dir is relative, cert rotation builds incorrect symlinks

[smarterclayton]

Symlinks relative to a working directory were being constructed to the
wrong location, leading to failure to refresh client certs.

@liggitt

[k8s-ci-robot]

@smarterclayton: Adding do-not-merge/release-note-label-needed because the release note process has not been followed.

One of the following labels is required "release-note", "release-note-action-required", or "release-note-none".
Please see: https://github.com/kubernetes/community/blob/master/contributors/devel/pull-requests.md#write-release-notes-if-needed.

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[mikedanese]

/lgtm

[k8s-github-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

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

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• staging/src/k8s.io/client-go/util/certificate/OWNERS [mikedanese,smarterclayton]

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[smarterclayton]

/retest

[fejta-bot]

/retest
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Review the full test history for this PR.

[fejta-bot]

/retest
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Review the full test history for this PR.

[k8s-github-robot]

/test all [submit-queue is verifying that this PR is safe to merge]

[k8s-github-robot]

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions here.