audiod: fix mode cycling

audiod: fix mode cycling

This was quite buggy all the time, but wasn't noticed due to the typo bug
which was fixed in 1b46ae4193cddb7d589b0f2f7d8158b84f7e9f6d.

Now, the status task no longer has an event handler as both its pre_select
and its post_select functions always succeed and the status task is supposed
to never terminate. Unlike the client task whose event handler now does all
the cleanup if the connection to para_server breaks down for whatever reason.