[PATCH] UPSTREAM: Fix ARP checking

Cherry-picked from
https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay/+/
master/net-misc/dhcpcd/files/patches/dhcpcd-6.8.2-UPSTREAM-Fix-ARP-
checking.patch.

Fix ARP checking logic and the usage of IN_IFF_TENTATIVE compiler flag
around ARP checking.

Upstream patch link:
http://roy.marples.name/projects/dhcpcd/info/fad4fae29d5d7dc9
http://roy.marples.name/projects/dhcpcd/info/9dcdaf2d1ef4a44d

BUG: 22956197
Change-Id: I1ba5c5d56a104cadf4566367408abb068b7e1268

Reviewed-on: https://chromium-review.googlesource.com/272614
1 file changed