fix parse devicePath issue on Azure Disk

[andyzhangx]

What type of PR is this?
/kind bug

What this PR does / why we need it:
fix parse devicePath issue on Azure Disk

There is some corner case that after attaching an Azure disk, disk device path is not displayed immediately under /dev/disk/azure/scsi1/lun?, instead it returns like /dev/sd?, which will make disk mount failure(like below failure), this PR also handles such corner case, if failed, it logs the error and then use azure API(diskController.GetDiskLun) to get disk LUN of that disk.

As I could observe, in VMSS, disk detection after disk attachment is slow, sometimes user would get below error, workaround is delete the pod and let k8s remount.

 Warning  FailedMount  1m (x6 over 13m)    kubelet, k8s-clcpyqmetcas-38966124-vmss000000  Unable to mount volumes for pod 'solr-0_default(6bbc79aa-2ab7-11e9-88e7-000d3ad25c8a)': timeout expired waiting for volumes to attach or mount for pod 'default'/'solr-0'. list of unmounted volumes=[solrhome]. list of unattached volumes=[solrhome]
 Warning  FailedMount  51s (x15 over 15m)  kubelet, k8s-clcpyqmetcas-38966124-vmss000000  MountVolume.WaitForAttach failed for volume 'pvc-04e61231-18c4-11e9-88e7-000d3ad25c8a' : cannot parse deviceInfo: /dev/sdf
Several unsuccessful restarts of k8s pod were attempted.  Then the k8s pod was removed from instance of VMSS (vmss000000) - so it was started on the new instance VMSS on which it started to work without problems.

Which issue(s) this PR fixes:

Fixes #74421

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

fix parse devicePath issue on Azure Disk

/kind bug
/assign @feiskyer
/priority important-soon
/sig azure

cc @khenidak

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: andyzhangx

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[andyzhangx]

@feiskyer PTAL

[feiskyer]

LGTM. Could you add unit tests for this?

[feiskyer]

/LGTM