Merge branch 'tcp-cwnd-undo-refactor'

Yuchung Cheng says:

====================
tcp cwnd undo refactor

This patch series consolidate similar cwnd undo functions
implemented by various congestion control by using existing
tcp socket state variable. The first patch fixes a corner
case in of cwnd undo in Reno and HTCP. Since the bug has
existed for many years and is very minor, we consider this
patch set more suitable for net-next as the major change
is the refactor itself.

- v1->v2
  Fix trivial compile errors
====================

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