|SUCCESS| net/iavf: fix interrupt callback race on close

[dpdklab at iol.unh.edu]

Test-Label: ai-code-review
Test-Status: SUCCESS
https://dpdk.org/patch/171276

_AI Code Review_

=== Patch Review: series.patch (via Claude) ===
Review date: 2026-10-14

# DPDK Patch Review

## ERRORS

None.

## WARNINGS

None.

## INFO

**Correctness: Race condition fix looks correct**

The patch correctly identifies and fixes a race condition in interrupt handler cleanup.
The change from `rte_intr_callback_unregister()` to `rte_intr_callback_unregister_sync()` 
prevents the interrupt thread from accessing freed resources after `dev->data` is set to NULL.

The commit message provides a clear explanation of:
- The failure mode (segfault when handler accesses NULL `dev->data`)
- Why the synchronous variant is safe (handler never closes/re-initializes the port itself)
- Why it won't deadlock (events are handed to iavf-event thread)

The fix is applied consistently to both locations (`iavf_dev_close()` and the 
`iavf_dev_init()` error path), matching the pattern used in `ice_dev_close()`.

**Note**: This is a correctness improvement over the existing code. The race window 
described is real and the fix is appropriate.

Review-Result: CLEAN