S2io: Fix for LRO Bugs

Resubmitting patch from Al Viro <viro@zeniv.linux.org.uk>, with subject -
[PATCH] s2io LRO bugs.
a) initiate_new_session() sets ->tcp_ack to ntohl(...); everything
   else stores and expects to find there the net-endian value.
b) check for monotonic timestamps in verify_l3_l4_lro_capable()
   compares the value sitting in TCP option (right there in the skb->data,
   net-endian 32bit) with the value picked from earlier packet.
   Doing that without ntohl() is an interesting idea and it might even
   work occasionally; unfortunately, it's quite broken.

Signed-off-by: Surjit Reang <surjit.reang@neterion.com>
Signed-off-by: Ramkrishna Vepa <ram.vepa@neterion.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: David S. Miller <davem@davemloft.net>