[CI] fix ref/cut signal order in cmp_pcm calls

Reason why this change is needed

• Some instances of cmp_pcm in the tests had the ref/cut file input the wrong way round

Description of the change

• Fix by switching the filenames

Affected operating points

• None, test-code-only change
• Test results are affected
  • for MAX_ABS_DIFF, same result, just sign-flipped
  • MLD should be same, I think, as it is an energy-based comparison
  • PEAQ could be quite different, but hard to predict
  • SSNR should be same in general, could be the case that some of thethresholding is different now
• One will not see differences in this MR, though