[BRIDGE]: Fix locking of set path cost.

This change goes with earlier change to get rid of
work queue for path cost. Now stp_set_path_cost does its own
locking. This is to allow it to call br_path_cost() which calls
ethtool interfaces (might sleep).
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/br_ioctl.c

@@ -291,12 +291,11 @@ static int old_dev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
 		if (!capable(CAP_NET_ADMIN))
 			return -EPERM;
 
-		spin_lock_bh(&br->lock);
 		if ((p = br_get_port(br, args[1])) == NULL)
 			ret = -EINVAL;
 		else
 			br_stp_set_path_cost(p, args[2]);
-		spin_unlock_bh(&br->lock);
+
 		return ret;
 	}