netvsp: handle eqe 135 followup

[erfrimod]

Follow-up to #2576

• Reorder the reconfigure subscription to before starting notifications.
• Adding debug tracing to skipped VF reconfiguration events.
• Fixing text in HWC test code.
• Removing pending VF reconfiguration from GDMA saved state. Modifying save state to fail when reconfiguration is pending.

[Copilot]

Pull request overview

This PR is a follow-up to PR #2576, addressing several issues identified after the initial implementation of VF reconfiguration support for netvsp.

Changes:

• Fixes a race condition by reordering VF reconfiguration subscription to occur before starting the notification task
• Removes vf_reconfiguration_pending from saved state and adds validation to prevent save/restore operations when VF reconfiguration is pending
• Adds debug tracing for skipped VF reconfiguration events to improve observability

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
vm/devices/net/mana_driver/src/save_restore.rs	Removes vf_reconfiguration_pending field from GdmaDriverSavedState struct
vm/devices/net/mana_driver/src/gdma_driver.rs	Adds validation to prevent save/restore with pending VF reconfig; initializes field to false on restore
vm/devices/net/gdma/src/hwc.rs	Improves error message context for VF reconfig test request
openhcl/underhill_core/src/emuplat/netvsp.rs	Reorders subscription call before notification task start (2 locations); adds debug tracing for skipped reconfig events