Fix VM info module for failed VM provisions

[JoostMuller-TomTom]

SUMMARY

Fixes usage of undeclared variables for virtual machines that failed to provision correctly.

ISSUE TYPE

• Bugfix Pull Request

COMPONENT NAME

azure_rm_virtualmachine_info.py

ADDITIONAL INFORMATION

serialize_vm() in azure_rm_virtualmachine_info.py fails with the message:

  msg: Error getting virtual machine None - local variable 'display_status' referenced before assignment

The value of instance for the failed-to-provision VM is:

{
  'hyperVGeneration': 'V1',
  'disks': [{ <snip> }],
  'statuses': [{
    'code': 'ProvisioningState/failed/NetworkingInternalOperationError',
    'level': 'Error',
    'displayStatus': 'Provisioning failed',
    'message': 'An unexpected error occured while processing the network profile of the VM. Please retry later.',
    'time': '2021-12-21T10:06:31.289877Z',
  }]
}

[JoostMuller-TomTom]

@Fred-sun: issue was introduced by #657, FYI.

[xuzhang3]

LGTM