net/smc: dev_put for netdev after usage of ib_query_gid()

For RoCEs ib_query_gid() takes a reference count on the net_device.
This reference count must be decreased by the caller.
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Reported-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Parav Pandit <parav@mellanox.com>
Fixes: 0cfdd8f9 ("smc: connection and link group creation")
Signed-off-by: David S. Miller <davem@davemloft.net>

net/smc/smc_core.c

@@ -380,10 +380,14 @@ static int smc_link_determine_gid(struct smc_link_group *lgr)
 		if (ib_query_gid(lnk->smcibdev->ibdev, lnk->ibport, i, &gid,
 				 &gattr))
 			continue;
-		if (gattr.ndev &&
-		    (vlan_dev_vlan_id(gattr.ndev) == lgr->vlan_id)) {
-			lnk->gid = gid;
-			return 0;
+		if (gattr.ndev) {
+			if (is_vlan_dev(gattr.ndev) &&
+			    vlan_dev_vlan_id(gattr.ndev) == lgr->vlan_id) {
+				lnk->gid = gid;
+				dev_put(gattr.ndev);
+				return 0;
+			}
+			dev_put(gattr.ndev);
 		}
 	}
 	return -ENODEV;