ADE: FAILED to find suitable passphrase file ...

A customer encrypted the **OS** disk on a Ubuntu VM (Canonical:UbuntuServer:16.04-LTS:latest)

AzureDiskEncryptionForLinux version is **1.1.0.17**

After the disk get encrypted, he rebooted the VM a few times without problem.
However after he redeployed the VM, he got the following error saying it cannot find the passphrase.

**Before re-deploy**:
```
mounting /dev/sdc1 on /tmp-keydisk-mount failed: No such device
Success loading keyfile!
...
mounting /dev/sdc1 on /tmp-keydisk-mount failed: No such device
Success loading keyfile!
```
**After re-deploy**:
```
mounting /dev/sdc1 on /tmp-keydisk-mount failed: No such device
FAILED to find suitable passphrase file ...
Try to enter your password:
```

We encrypted the OS disk of a second VM using the same vault/key but the same issue occurred after redeploying the VM.