Crash in kernel mixer code during system shutdown

[Paul Goyette <paul%whooppee.com@localhost>]

I just did a shutdown/reboot of my 8.99.1 system (sources about 2 days 
old), and it crashed in the kernel mixer code.  Manually transcribed 
traceback is

	mixer_close.part.28 + 0x21   (strange symbol name...)
	closef + 0x54
	fd_close + 0x20
	syscall + 0x1d8

The current process was reported as pulseaudio.

Interestingly, the system had been up for about 24 hours, but the audio 
synthesized speaker bell had stopped working several hours ago, for no 
discernible reason.  I was rebooting to get my bell back, and the crash 
resulted.

+------------------+--------------------------+----------------------------+
| Paul Goyette     | PGP Key fingerprint:     | E-mail addresses:          |
| (Retired)        | FA29 0E3B 35AF E8AE 6651 | paul at whooppee dot com   |
| Kernel Developer | 0786 F758 55DE 53BA 7731 | pgoyette at netbsd dot org |
+------------------+--------------------------+----------------------------+