fix a bug where opening /dev/dsp twice resulted in it being busy until reboot

sys/dev/sound/pcm/dsp.c

@@ -141,8 +141,11 @@ dsp_close(snddev_info *d, int chan, int devtype)
 {
 	pcm_channel *rdch, *wrch;
 
+#if 0
+	/* enable this if/when every close() is propagated here */
 	d->ref[chan]--;
 	if (d->ref[chan]) return 0;
+#endif
 	d->flags &= ~SD_F_TRANSIENT;
 	rdch = d->arec[chan];
 	wrch = d->aplay[chan];