ALSA: compress: fix partial_drain completion state

On partial_drain completion we should be in SNDRV_PCM_STATE_RUNNING
state, so set that for partially draining streams in
snd_compr_drain_notify() and use a flag for partially draining streams

While at it, add locks for stream state change in
snd_compr_drain_notify() as well.

Fixes: f44f2a54 ("ALSA: compress: fix drain calls blocking other compress functions (v6)")
Signed-off-by: Vinod Koul <vkoul@kernel.org>