net/mlx5: Remove redundant check from mlx5_esw_query_vport_vhca_id()

Since mlx5_esw_query_vport_vhca_id() could be called either from
mlx5_esw_vport_enable() or mlx5_esw_vport_disable() where the
the check is done, this is always false here.
Remove the redundant check.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Shay Drory <shayd@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>