RDMA/mlx5: Enable sniffer when device is in switchdev mode

In order to allow sniffer when the RDMA device is in switchdev mode, we
don't need to set the source port when creating the sniffer rule.

Link: https://lore.kernel.org/r/20200803060214.15328-1-leon@kernel.org


Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>