Various routines were putting a full struct tcp_sock on
the local stack.  What they really wanted was a subset
of this information when doing TCP options processing
when we only have a mini-socket (for example in SYN-RECVD
and TIME_WAIT states).

Therefore pull out the needed information into a sub-struct
and use that in the TCP options processing routines.
Signed-off-by: Arnaldo Carvalho de Melo <acme@conectiva.com.br>
Signed-off-by: David S. Miller <davem@davemloft.net>