|SUCCESS| net/virtio: fix checksum offset check in Rx path

[dpdklab at iol.unh.edu]

Test-Label: ai-code-review
Test-Status: SUCCESS
https://dpdk.org/patch/171666

_AI Code Review_

=== Patch Review: series.patch (via Claude) ===
Review date: 2026-10-19

# DPDK Patch Review

## ERRORS

None.

## WARNINGS

None.

## INFO

### Checksum offset bounds check improvement

The patch changes the bounds check from `off + 1` to `off + sizeof(uint16_t)` before writing a 16-bit checksum value.

**Analysis:**
- The code writes a `uint16_t` value at offset `off`
- Original check `off + 1` only ensures 1 byte is available, not 2
- New check `off + sizeof(uint16_t)` correctly ensures 2 bytes are available
- This prevents potential out-of-bounds writes when the checksum field straddles the end of the first segment

**Verdict:** The fix is correct. The original code had an off-by-one error in the bounds check that could allow writing 1 byte beyond the segment boundary.

**Code quality note:** Using `sizeof(uint16_t)` instead of the literal `2` improves maintainability and makes the intent explicit (we need room for a uint16_t, not just "2 bytes").

The patch correctly targets both occurrences of this pattern in the virtio driver.

Review-Result: CLEAN