Merge branch 'mptcp-sync-the-msk-sndbuf-at-accept-time'

Merge branch 'mptcp-sync-the-msk-sndbuf-at-accept-time'

Matthieu Baerts says:

====================
mptcp: sync the msk->sndbuf at accept() time

On passive MPTCP connections, the MPTCP socket send buffer doesn't have
the expected size at accept() time.

Patch 1 fixes the regression introduced in v6.7, while the following one
validates the fix in the selftests.

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
====================

Link: https://patch.msgid.link/20260420-net-mptcp-sync-sndbuf-accept-v1-0-e3523e3aeb44@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>