ALSA: compress: Make sure we trigger STOP before closing the stream.

Currently we assume that userspace will shut down the compressed stream
correctly. However, if userspcae dies (e.g. cplay & ctrl-C) we dont
stop the stream before freeing it.

This now checks that the stream is stopped before freeing.

Signed-off-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>