si-audio-adapter: make sure formats is valid before iterating

6 jobs for adapter-fix in 1 minute and 42 seconds (queued for 9 seconds)
Status Name Job ID Coverage
  Container
passed container_fedora #14875846

00:00:27

passed container_ubuntu #14875847

00:00:14

 
  Build
passed build_on_fedora_no_docs #14875849

00:01:13

passed build_on_fedora_with_docs #14875848

00:01:15

passed build_on_ubuntu_no_gir #14875851

00:01:13

passed build_on_ubuntu_with_gir #14875850

00:01:14