mlxsw: spectrum: Add missing rollback in flood configuration

mlxsw: spectrum: Add missing rollback in flood configuration

When we fail to set the flooding configuration for the broadcast and
unregistered multicast traffic, we should revert the flooding
configuration of the unknown unicast traffic.

Fixes: ec77ece37e59 ("mlxsw: spectrum: Add support for flood control")
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>