[pulseaudio-discuss] alsa-sink: fix revents bug when meet underrun

[Pierre-Louis Bossart]

Makes sense, the polled case should only happen for POLLOUT. But this is
mainly cosmetic in an error case that shouldn't happen.
-Pierre

> There's similar case for capture. So update the patch.
> 
> 
> Date: Fri, 5 Aug 2011 10:33:17 -0400
> Subject: [PATCH] alsa: resets POLLOUT event
> 
> revents marked as POLLOUT|POLLERR|POLLWRNORM in "underrun" case, that
> will
> trigger unexpected log "ALSA woke us up to write new data to the
> device, but
> there was acturally nothing to write...".