Decrease the audio output level of a given audio device.
#include <audio/audio_manager_volume.h>
int audio_manager_decrease_output_level(audio_manager_device_t dev)
The audio device that the decrease is applied to.
The audio_manager_decrease_output_level() function decreases the audio output level of a given audio device. The step of the output level decrease is defined by the particular audio device.
EOK upon success, negative errno upon failure.