switchdev: bridge: Check return code is not EOPNOTSUPP

When NET_SWITCHDEV=n, switchdev_port_attr_set simply returns EOPNOTSUPP.
In this case we should not emit errors and warnings to the kernel log.

Reported-by: Sander Eikelenboom <linux@eikelenboom.it>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Fixes: 0bc05d58 ("switchdev: allow caller to explicitly request
attr_set as deferred")
Fixes: 6ac311ae ("Adding switchdev ageing notification on port
bridged")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>