net/smc: adapt SMC client code to use the LLC flow

Change the code that processes the SMC client part of connection
establishment to use the LLC flow framework (CONFIRM_LINK request
messages).

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>