Fix infinite loop in a2dp-sink
This PR fixes an infinite loop that always happens when playing audio with a2dp-sink.
Steps to reproduce:
- Run pipewire with the example media-session
- Connect a bluetooth speaker and wait for the a2dp-sink node to be created
- Try to play audio using the example audio-src executable
- No audio is played and the a2dp-sink gets into an infinite loop state
The audio plays without issues if we use this patch