simplify and fix fit example RealLifeReflectometryFitting.py

Too slow. No plots during fitting.

Fails in

def plot_result(sim_result, ref_result, bin_start=0, bin_end=-1):
    ...
    plt.plot(
        get_real_data_axis(bin_start, bin_end)*180/np.pi,
        get_real_data_values(bin_start, bin_end), sim_result.axis(),
        sim_data, ref_result.axis(), ref_data)

with

Traceback (most recent call last):
  File "/G/sw/ba/build/../Examples/fit/specular/RealLifeReflectometryFitting.py", line 297, in <module>
    plot_result(run_simulation(fit_data), run_simulation(ref_data))
  File "/G/sw/ba/build/../Examples/fit/specular/RealLifeReflectometryFitting.py", line 271, in plot_result
    get_real_data_values(bin_start, bin_end), sim_result.axis(),
AttributeError: 'SimulationResult' object has no attribute 'axis'