Address two issues in the inline pppoe encapsulation:
- Add needs_gso_segment flag to segment PPPoE packets in software
given that there is no GSO support for this.
- Use FLOW_OFFLOAD_XMIT_DIRECT since neighbour cache is not available
in point-to-point device, use the hardware address that is obtained
via flowtable path discovery (ie. fill_forward_path).
Fixes: 18d27bed08 ("netfilter: flowtable: inline pppoe encapsulation in xmit path")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>