eBPF defines this as BPF_TUNLEN_MAX and OVS just uses the hard-coded
value inside struct sw_flow_key. Thus, add and use IP_TUNNEL_OPTS_MAX
for this, which makes the code a bit more generic and allows to remove
BPF_TUNLEN_MAX from eBPF code.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>