Merge branch 'lift-udp_segment-restriction-for-egress-via-device-w-o-csum-offload'

Merge branch 'lift-udp_segment-restriction-for-egress-via-device-w-o-csum-offload'

Jakub Sitnicki says:

====================
Lift UDP_SEGMENT restriction for egress via device w/o csum offload

This is a follow-up to an earlier question [1] if we can make UDP GSO work
with any egress device, even those with no checksum offload capability.
That's the default setup for TUN/TAP.

Because there is a change in behavior - sendmsg() does no longer return
EIO error - I'm submitting through net-next tree, rather than net,
as per Willem's advice.

[1] https://lore.kernel.org/netdev/87jzqsld6q.fsf@cloudflare.com/

v1: https://lore.kernel.org/r/20240622-linux-udpgso-v1-0-d2344157ab2a@cloudflare.com
====================

Link: https://patch.msgid.link/20240626-linux-udpgso-v2-0-422dfcbd6b48@cloudflare.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>