net/smc: fix handling of delete link requests

As smc client the delete link requests are assigned to the flow when
_any_ flow is active. This may break other flows that do not expect
delete link requests during their handling. Fix that by assigning the
request only when an add link flow is active. With that fix the code
for smc client and smc server is the same, so remove the separate
handling.

Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Fixes: 9ec6bf19

 ("net/smc: llc_del_link_work and use the LLC flow for delete link")
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>