fix anogan plot_learning_curves label issue.

[lambertsbennett]

Currently the y-label is overwritten and says 'Iter' instead of 'Loss'. This is a simple one line replacement to fix the plot labels for Anogan's plot_learning_curves plot.

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[lambertsbennett]

This issue was present for ALAD as well, so I fixed the typo there too.

[yzhao062]

Thank you!