fix account key getting logic in azure

[beautytiger]

What type of PR is this?
/kind bug

What this PR does / why we need it:
Current cache key logic in getStorageAccountKey is confusing and do not make much sense, fix it by moving it into if condition clause.

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

NONE

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

/cc @liggitt
/assign @liggitt

[k8s-ci-robot]

Hi @beautytiger. 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 /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.

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[liggitt]

/unassign
/assign @andyzhangx

[andyzhangx]

/ok-to-test
/test pull-kubernetes-e2e-aks-engine-azure

[beautytiger]

/retest

[beautytiger]

kindly ping @andyzhangx

[andyzhangx]

/lgtm
/approve
/priority important-soon

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: andyzhangx, beautytiger

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• staging/src/k8s.io/legacy-cloud-providers/azure/OWNERS [andyzhangx]

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