The replay infrastructure shouldn't depend on internals of audio/.
(st_sample is an internal implementation detail and could be different)
Let audio drive the audio samples recording/replaying.
Notice also we don't need to save & restore the internal ring "wpos",
all replay should care about is the number of samples and the samples.
Bump the replay version.
Reviewed-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>