pulse: Wake up waiting operation once on EOL.
pulse: Wake up waiting operation once on EOL.

When enumerating devices, the main thread was being unnecessarily
woken up for each sink/source.  Change to just signal when the
end-of-list (EOL) is reached.

Also removes use of goto which is, in my book, a win.

kinetiknz/cubeb,kinetiknz/cubeb,kinetiknz/cubeb