Crash initializing audio device

E.g. tests/functional/test_m68k_q800.py

ALSA lib confmisc.c:165:(snd_config_get_card) Cannot get card index for 0
couldn't open play stream: No such file or directory
sndio: failed to open device
ALSA lib confmisc.c:165:(snd_config_get_card) Cannot get card index for 0
couldn't open play stream: No such file or directory
sndio: failed to open device
audio: Could not create a backend for voice `asc.out'

Thread 1 "qemu-system-m68" received signal SIGSEGV, Segmentation fault.
AUD_get_buffer_size_out (sw=0x0) at ../src/audio/audio.c:908
908	    return sw->hw->samples * sw->hw->info.bytes_per_frame;

In hw/audio/asc.c, asc_realize,

655	    s->voice = AUD_open_out(&s->card, s->voice, "asc.out", s, asc_out_cb,
656	                            &as);
657	    s->shift = 1;
658	    s->samples = AUD_get_buffer_size_out(s->voice) >> s->shift;

we do not check for failure from AUD_open_out. But for that matter, neither does any other usage of AUD_open_out, nor does AUD_open_out really have a way to emit a proper Error return.