net: ipv4: Fix ARP probe check in address conflict detection

[anhuba]

The second condition needs to check ARP probes only

Fixes #80429

[github-actions]

Hello @anhuba, and thank you very much for your first pull request to the Zephyr project!
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[jukkar]

Could you also add text from your issue to the commit message, at least this could be put there

The ACD is not properly implemented as described in RFC5227 ch. 2.1.1
The implementation incorrectly detects an IP conflict, if an ARP request is received for the target IP.
The reason is that the current implementation checks for ARP requests instead of ARP probes.

[rlubos]

The fix itself looks good, but the branch needs some cleanup:

• Please use rebase instead of merge, no merge commits allowed
• The commit message in the fix commit is missing signoff entry.

[rlubos]

Please squash the commits (and add signoff entry).

[anhuba]

changed commit message and elminated local variable

[rlubos]

Some more issues with the commit message:

6: UC4 Commit message body line exceeds max length (103>75): "The implementation incorrectly detects an IP conflict, if an ARP request is received for the target IP."
7: UC4 Commit message body line exceeds max length (92>75): "The reason is that the current implementation checks for ARP requests instead of ARP probes."

f453f3b45490a2d7a5d45d727b4609dd97cac815: author email (anhuba <113986680+anhuba@users.noreply.github.com>) needs to match one of the signed-off-by entries.
f453f3b45490a2d7a5d45d727b4609dd97cac815: author email (anhuba <113986680+anhuba@users.noreply.github.com>) does not follow the syntax: First Last .

[github-actions]

Hi @anhuba!
Congratulations on getting your very first Zephyr pull request merged 🎉🥳. This is a fantastic achievement, and we're thrilled to have you as part of our community!

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Thank you for your valuable input, and we look forward to seeing more of your contributions in the future! 🪁