avahi: remove useless avahi_threaded_poll_stop() from error path
avahi: remove useless avahi_threaded_poll_stop() from error path

Error path is never triggered after avahi_threaded_poll_start().
Even if it was, thread should probably be stopped before freeing avahi client ...

xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc