net/smc: simplify normal link termination

smc_lgr_terminate() and smc_lgr_terminate_sched() both result in soft
link termination, smc_lgr_terminate_sched() is scheduling a worker for
this task. Take out complexity by always using the termination worker
and getting rid of smc_lgr_terminate() completely.

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