Merge branch 'mptcp-fixes-for-5-19'

Mat Martineau says:

====================
mptcp: Fixes for 5.19

Several categories of fixes from the mptcp tree:

Patches 1-3 are fixes related to MP_FAIL and FASTCLOSE, to make sure
MIBs are accurate, and to handle MP_FAIL transmission and responses at
the correct times. sk_timer conflicts are also resolved.

Patches 4 and 6 handle two separate race conditions, one at socket
shutdown and one with unaccepted subflows.

Patch 5 makes sure read operations are not blocked during fallback to
TCP.

Patch 7 improves the diag selftest, which were incorrectly failing on
slow machines (like the VMs used for CI testing).

Patch 8 avoids possible symbol redefinition errors in the userspace
mptcp.h file.

Patch 9 fixes a selftest build issue with gcc 12.
====================

Link: https://lore.kernel.org/r/20220628010243.166605-1-mathew.j.martineau@linux.intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>