Merge branch 'mptcp-miscellaneous-fixes-and-a-new-test-case'

Merge branch 'mptcp-miscellaneous-fixes-and-a-new-test-case'

Mat Martineau says:

====================
mptcp: Miscellaneous fixes and a new test case

Patches 1 and 3 remove helpers that were iterating over the subflow
connection list without proper locking. Iteration was not needed in
either case.

Patch 2 fixes handling of MP_FAIL timeout, checking for orphaned
subflows instead of using the MPTCP socket data lock and connection
state.

Patch 4 adds a test for MP_FAIL timeout using tc pedit to induce checksum
failures.
====================

Link: https://lore.kernel.org/r/20220518220446.209750-1-mathew.j.martineau@linux.intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>