T7819: VPP do not override driver if it is already done

[sever-sever]

Change summary

Do not override already overridden drivers

Fixes this case:

Traceback (most recent call last):
  File "/usr/libexec/vyos/services/vyos-configd", line 156, in run_script
    script.apply(c)
  File "/usr/libexec/vyos/conf_mode/vpp.py", line 613, in apply
    control_host.override_driver(
  File "/usr/lib/python3/dist-packages/vyos/vpp/control_host.py", line 138, in override_driver
    Path('/sys/module/vfio_pci/drivers/pci:vfio-pci/new_id').write_text(
  File "/usr/lib/python3.11/pathlib.py", line 1079, in write_text
    with self.open(mode='w', encoding=encoding, errors=errors, newline=newline) as f:
FileExistsError: [Errno 17] File exists

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Code style update (formatting, renaming)
• Refactoring (no functional changes)
• Migration from an old Vyatta component to vyos-1x, please link to related PR inside obsoleted component
• Other (please describe):

Related Task(s)

• https://vyos.dev/T7819

Related PR(s)

How to test / Smoketest result

Checklist:

• I have read the CONTRIBUTING document
• I have linked this PR to one or more Phabricator Task(s)
• I have run the components SMOKETESTS if applicable
• My commit headlines contain a valid Task id
• My change requires a change to the documentation
• I have updated the documentation accordingly

[github-actions]

👍
No issues in PR Title / Commit Title

[Copilot]

Pull Request Overview

This PR fixes a FileExistsError that occurs when VPP attempts to override a driver that has already been overridden. The fix adds exception handling to gracefully handle the case where the vendor/device ID pair is already registered with vfio-pci.

Key changes:

• Added try-except block around the vfio-pci new_id write operation
• FileExistsError is now silently ignored (expected behavior)
• Generic exceptions are caught and logged as warnings

Comments suppressed due to low confidence (1)

python/vyos/vpp/control_host.py:144

• 'except' clause does nothing but pass and there is no explanatory comment.

        except FileExistsError:

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[github-actions]

CI integration 👍 passed!

Details

CI logs

• CLI Smoketests (no interfaces) 👍 passed
• CLI Smoketests VPP 👍 passed
• CLI Smoketests (interfaces only) 👍 passed
• Config tests 👍 passed
• Config tests VPP 👍 passed
• RAID1 tests 👍 passed
• TPM tests 👍 passed