net/mlx5e: E-Switch, Fix comparing termination table instance

The pkt_reformat pointer being saved under flow_act and not
dest attribute in the termination table instance.
Fix the comparison pointers.

Also fix returning success if one pkt_reformat pointer is null
and the other is not.

Fixes: 249ccc3c ("net/mlx5e: Add support for offloading traffic from uplink to uplink")
Signed-off-by: Roi Dayan <roid@nvidia.com>
Reviewed-by: Chris Mi <cmi@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>