check-va-api: Do not stop if one decoding profile fails

Previously if we were able to create a configuration for a specific decoding profile we assumed that this profile was working correctly, and if it was not we returned an error.

Instead now we always fallback to the next decoding profile, until we find one that works or run out of options.

This fixes an issue with Intel iGPUs that are able to create a H264Main configuration but then they fail to actually do the rendering. It may be due to the fact that they don't like the specific profile and image format combination that we use, or something else. Because MPEG2 Simple seems to be working just fine, this fix should be enough for now.