net/smc: handle state SMC_PEERFINCLOSEWAIT correctly

A state transition from closing state SMC_PEERFINCLOSEWAIT to closing
state SMC_APPFINCLOSEWAIT is not allowed. Once a closing indication
from the peer has been received, the socket reaches state SMC_CLOSED.

And receiving a peer_conn_abort just changes the state of the socket
into one of the states SMC_PROCESSABORT or SMC_CLOSED;
sending a peer_conn_abort occurs in smc_close_active() for state
SMC_PROCESSABORT only.

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