tcp: Revert reset of deferred accept changes in 2.6.26

Ingo's system is still seeing strange behavior, and he
reports that is goes away if the rest of the deferred
accept changes are reverted too.

Therefore this reverts e4c78840
("[TCP]: TCP_DEFER_ACCEPT updates - dont retxmt synack") and
539fae89

 ("[TCP]: TCP_DEFER_ACCEPT
updates - defer timeout conflicts with max_thresh").

Just like the other revert, these ideas can be revisited for
2.6.27

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