Saran

// Controller
public function updatepenilaian() {
    $this->apotik_model->update_data_penunjang();
    redirect(site_url('seleksi'));
}

// Model
function update_data_penunjang() {
    $idpeserta = $this->input->post('nopeserta');
    // Atau
    $idpeserta = $this->uri->segment(3);

    $data = array(
            'pointkelengkapan'  => $this->input->post('pointkelengkapan'),
            'pointopini'        => $this->input->post('pointopini'),
            'pointinterview'    => $this->input->post('pointinterview')
            );

    $this->db->where('nopeserta', $idpeserta);
    $this->db->update('table_name', $data);
}