Merge branch 'mptcp-misc-fixes-for-v6-19-rc1'

Matthieu Baerts says:

====================
mptcp: misc fixes for v6.19-rc1

Here are various unrelated fixes:

- Patches 1-2: ignore unknown in-kernel PM endpoint flags instead of
  pretending they are supported. A fix for v5.7.

- Patch 3: avoid potential unnecessary rtx timer expiration. A fix for
  v5.15.

- Patch 4: avoid a deadlock on fallback in case of SKB creation failure
  while re-injecting.
====================

Link: https://patch.msgid.link/20251205-net-mptcp-misc-fixes-6-19-rc1-v1-0-9e4781a6c1b8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>