Merge branch 'net-fix-passive-tfo-socket-having-invalid-napi-id'

David Wei says:

====================
net: fix passive TFO socket having invalid NAPI ID

Found a bug where an accepted passive TFO socket returns an invalid NAPI
ID (i.e. 0) from SO_INCOMING_NAPI_ID. Add a selftest for this using
netdevsim and fix the bug.

Patch 1 is a drive-by fix for the lib.sh include in an existing
drivers/net/netdevsim/peer.sh selftest.

Patch 2 adds a test binary for a simple TFO server/client.

Patch 3 adds a selftest for checking that the NAPI ID of a passive TFO
socket is valid. This will currently fail.

Patch 4 adds a fix for the bug.
====================

Link: https://patch.msgid.link/20250617212102.175711-1-dw@davidwei.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>