Merge branch 'mptcp-misc-fixes-for-v6-17-rc6'

Matthieu Baerts says:

====================
mptcp: misc fixes for v6.17-rc6

Here are various unrelated fixes:

- Patch 1: Fix a wrong attribute type in the MPTCP Netlink specs. A fix
  for v6.7.

- Patch 2: Avoid mentioning a deprecated MPTCP sysctl knob in the doc. A
  fix for v6.15.

- Patch 3: Handle new warnings from ShellCheck v0.11.0. This prevents
  some warnings reported by some CIs. If it is not a good material for
  'net', please drop.
====================

Link: https://patch.msgid.link/20250908-net-mptcp-misc-fixes-6-17-rc5-v1-0-5f2168a66079@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>