netvsp: eqe 135 handling clashing with fhr

[erfrimod]

Problems happen when device arrival / removal occur during VF Reconfiguration delays and waits. Modifying the behavior in VF Manager to consider device arrival/removal to indicate that the old VF is gone and the reconfiguration should be abandoned.

Example: EQE 135 arrives -> delay -> FHR -> device removal

• If ManaDeviceRemoved fires during Reconfiguring, clears vf_reconfig_backoff → no more retries
• If ManaDeviceArrived fires while vf_reconfig_backoff is Some, code panics (assert!)
• If the uevent add occurs while state is Reconfiguring, the handling code maps it to Continue → event discarded

[Copilot]

Pull request overview

Adjusts the netvsp VF manager worker’s reconfiguration state machine to better tolerate VF arrival/removal events that occur during VF reconfiguration delays (e.g., EQE 135 + FHR timing), avoiding panics and inappropriate retry behavior.

Changes:

• Treat uevent “device exists” notifications as ManaDeviceArrived even while in Reconfiguring.
• Replace a panic on device arrival during reconfig backoff with “abandon reconfiguration” behavior (clears backoff + logs).
• On device removal, clear any outstanding reconfig backoff (with logging) rather than silently resetting.

[github-actions]

At least one Petri test failed.

[ben-zen]

LGTM