Automatic merge from submit-queue (batch tested with PRs 44687, 44689, 44661)
Fix panic when using `kubeadm init` with vsphere cloud-provider
**What this PR does / why we need it**:
Check if the reference is nil when finding machine reference by UUID.
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes#44603
**Special notes for your reviewer**:
This is just a quick fix for the panic.
**Release note**:
```release-note
NONE
```