mlxsw: spectrum_switchdev: Don't ignore deletions of learned MACs

[ Upstream commit ad0b9d94182be8356978d220c82f9837cffeb7a9 ]

Demands to remove FDB entries should be honored even if the FDB entry in
question was originally learned, and not added by the user. Therefore
ignore the added_by_user datum for SWITCHDEV_FDB_DEL_TO_DEVICE.

Fixes: 816a3bed ("switchdev: Add fdb.added_by_user to switchdev notifications")
Signed-off-by: Petr Machata <petrm@mellanox.com>
Suggested-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>