ard.lua: cleanup
ard.lua: cleanup

* remove superfluous fsk table from test_availability()
* s/films/videos/ in test_availability()
* move the call to test_availability() into iter_formats(), so it
  gets always executed
* remove superfluous match in container_from()

DangerCove/libquvi-scripts,alech/libquvi-scripts,DangerCove/libquvi-scripts,alech/libquvi-scripts,legatvs/libquvi-scripts,legatvs/libquvi-scripts