bridge: Make br_is_nd_neigh_msg() accept pointer to "const struct sk_buff"The skb_buff struct in br_is_nd_neigh_msg() is never modified. Mark it asconst.Signed-off-by: Ted Chen <znscnchen@gmail.com>Acked-by: Nikolay Aleksandrov <razor@blackwall.org>Link: https://patch.msgid.link/20250104083846.71612-1-znscnchen@gmail.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>