net/smc: adjust net_device refcount

smc_pnet_fill_entry() uses dev_get_by_name() adding a refcount to ndev.
The following smc_pnet_enter() has to reduce the refcount if the entry
to be added exists already in the pnet table.
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/smc/smc_pnet.c

@@ -181,9 +181,11 @@ static int smc_pnet_enter(struct smc_pnetentry *new_pnetelem)
 			     sizeof(new_pnetelem->ndev->name)) ||
 		    smc_pnet_same_ibname(pnetelem,
 					 new_pnetelem->smcibdev->ibdev->name,
-					 new_pnetelem->ib_port))
+					 new_pnetelem->ib_port)) {
+			dev_put(pnetelem->ndev);
 			goto found;
 		}
+	}
 	list_add_tail(&new_pnetelem->list, &smc_pnettable.pnetlist);
 	rc = 0;
 found: