Merge branch 'mptcp-fixes-addressing-syzbot-reports'

Matthieu Baerts says:

====================
mptcp: fixes addressing syzbot reports

Recently, a few issues linked to MPTCP have been reported by syzbot. All
the remaining ones are addressed in this series.

- Patch 1: Address "KMSAN: uninit-value in mptcp_incoming_options (2)".
  A fix for v5.11.

- Patch 2: Address "WARNING in mptcp_pm_nl_set_flags (2)". A fix for
  v5.18.

- Patch 3: Address "WARNING in __mptcp_clean_una (2)". A fix for v6.4,
  backported up to v6.1.
====================

Link: https://patch.msgid.link/20250123-net-mptcp-syzbot-issues-v1-0-af73258a726f@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>