Redundant checks for not-supplied offset parameters in invoker

[inducer]

Visible in https://gist.github.com/matthiasdiener/b50910994b638097c37c9162f2005982, as flagged in illinois-ceesd/mirgecom#1101. Interspersed between enqueues.

Seems like this is mostly about offset parameters.

Also:

• Incorrect error messages in those.

Example:

    if _actx_in_1_6_ox_mass_0_offset is None:
        raise RuntimeError("input argument '{var_descr.name}' must be supplied")
    if _pt_data_141_offset is None:
        raise RuntimeError("input argument '{var_descr.name}' must be supplied")
    if dof_pick_list_indices_10_offset is None:
        raise RuntimeError("input argument '{var_descr.name}' must be supplied")
    if dof_pick_list_indices_11_offset is None:
        raise RuntimeError("input argument '{var_descr.name}' must be supplied")
    if dof_pick_lists_10_offset is None:
        raise RuntimeError("input argument '{var_descr.name}' must be supplied")
    if dof_pick_lists_11_offset is None:
        raise RuntimeError("input argument '{var_descr.name}' must be supplied")
    if from_el_indices_16_offset is None:
        raise RuntimeError("input argument '{var_descr.name}' must be supplied")

cc @matthiasdiener