Error in az vm boot-diagnostics get-boot-log

### **This is autogenerated. Please review and update as needed.**

## Describe the bug

**Command Name**
`az vm boot-diagnostics get-boot-log`

**Errors:**
```
'RetrieveBootDiagnosticsDataResult' object has no attribute 'done'
Traceback (most recent call last):
python3.6/site-packages/knack/cli.py, ln 231, in invoke
cmd_result = self.invocation.execute(args)
cli/core/commands/__init__.py, ln 657, in execute
raise ex
cli/core/commands/__init__.py, ln 720, in _run_jobs_serially
results.append(self._run_job(expanded_arg, cmd_copy))
cli/core/commands/__init__.py, ln 691, in _run_job
result = cmd_copy(params)
cli/core/commands/__init__.py, ln 328, in __call__
return self.handler(*args, **kwargs)
azure/cli/core/__init__.py, ln 807, in default_command_handler
return op(**command_args)
cli/command_modules/vm/custom.py, ln 1553, in get_boot_log
uris = LongRunningOperation(cmd.cli_ctx)(poller)
cli/core/commands/__init__.py, ln 958, in __call__
while not poller.done():
AttributeError: 'RetrieveBootDiagnosticsDataResult' object has no attribute 'done'
```

## To Reproduce:
Steps to reproduce the behavior. Note that argument values have been redacted, as they may contain sensitive information.

- `az vm boot-diagnostics get-boot-log --resource-group {} --name {}`

## Expected Behavior

## Environment Summary
```
Linux-5.12.0-1-default-x86_64-with
Python 3.6.10
Installer: DOCKER

azure-cli 2.22.1

```
## Additional Context

# Additional info

The affected machine is stuck while booting. If required I can give you the name and subscription ID of the machine. Please contact me via felix.niederwanger@suse.de in this case. Thank you!