The operation of adding VLANs on a port via switchdev ops can fail and
we need to be prepared for it. If we do not rollback hardware operations
following a failure, hardware and software will remain in an
inconsistent state.

Solve that by adding suitable error paths to __mlxsw_sp_port_vlans_add.
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>