Merge branch 'sctp-plpmtud-fixes'

Xin Long says:

====================
sctp: a couple of fixes for PLPMTUD

Four fixes included in this patchset:

  - fix the packet sending in Error state.
  - fix the timer stop when transport update dst.
  - fix the outer header len calculation.
  - fix the return value for toobig processing.
====================

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