net: bonding: Give bond_set_dev_addr() a return value

Before NETDEV_CHANGEADDR, bond driver should emit NETDEV_PRE_CHANGEADDR,
and allow consumers to veto the address change. To propagate further the
return code from NETDEV_PRE_CHANGEADDR, give the function that
implements address change a return value.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>