[evlatests] Polarizations are correctly labeled

[Michael Rupen]

I took some data this afternoon (C_osro_001.55375.841937592595) in which
I turned off the sampler for ea09-A (RCP).  This showed up correctly in
missing data for:

    ea09 IF1-RR,

    ea01-ea08 -> ea09 IF1-LR

    ea09 -> ea11-ea28 IF1-RL

So I think the cross-polarization labels are still fine.

                -- Michael