Use BPF_REG_1 for source and destination of gso_segs read,
to exercise "bpf: fix access to skb_shared_info->gso_segs" fix.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Suggested-by: NStanislav Fomichev <sdf@google.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>