net/mlx5e: Fix adding encap rules to slow path

On some devices the ignore flow level cap is not supported and we
shouldn't use it. Setting the dest ft with mlx5_chains_get_tc_end_ft()
already gives the correct end ft if ignore flow level cap is supported
or not.

Fixes: 39ac237c ("net/mlx5: E-Switch, Refactor chains and priorities")
Signed-off-by: Roi Dayan <roid@nvidia.com>
Reviewed-by: Paul Blakey <paulb@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>