Instead of checking for the audodev state in each code path, centralize
the check into the initialize function itself to make it safe to call it
at any time.

Signed-off-by: Geoffrey McRae <geoff@hostfission.com>
Message-id: 20200613040518.38172-7-geoff@hostfission.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>