Merge branch 'mptcp-Miscellaneous-fixes'

Mat Martineau says:

====================
mptcp: Miscellaneous fixes

Here are some MPTCP fixes for the -net tree, addressing various issues
we have seen thanks to syzkaller and other testing:

Patch 1 correctly propagates errors at connection time and for TCP
fallback connections.

Patch 2 sets the expected poll() events on SEND_SHUTDOWN.

Patch 3 fixes a retranmit crash and unneeded retransmissions.

Patch 4 fixes possible uninitialized data on the error path during
socket creation.

Patch 5 addresses a problem with MPTCP window updates.

Patch 6 fixes a case where MPTCP retransmission can get stuck.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>