Merge branch 'mptcp-various-bugfixes-and-improvements'

Florian Westphal says:

====================
mptcp: various bugfixes and improvements

This series contains the following mptcp bug fixes:

1. Fix crash on tcp fallback when userspace doesn't provide a 'struct
   sockaddr' to accept().
2. Close mptcp socket only when all subflows have closed, not just the first.
3. avoid stream data corruption when we'd receive identical mapping at the
    exact same time on multiple subflows.
4. Fix "fn parameter not described" kerneldoc warnings.
====================

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