net/smc: restructure client and server code in af_smc

This patch splits up the functions smc_connect_rdma and smc_listen_work
into smaller functions.

Signed-off-by: Hans Wippel <hwippel@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>