__update(): Jeremy Hylton reports occurances of sunaudiodev.error

__update(): Jeremy Hylton reports occurances of sunaudiodev.error
(interrupted system call) when getting the device information.  I've
never seen it, but this patch should take care of the problem.

If we get that exception and we're polling, just return since we'll
wake up again soon and get the right information.  If we're not
polling, try 4 times and then give up.