Up until this point we've accepted replay window settings greater than
32 but our bit mask can only accomodate 32 packets.  Thus any packet
with a sequence number within the window but outside the bit mask would
be accepted.

This patch causes those packets to be rejected instead.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>