Asoc: msm: qdsp6v2: Track compress stream open properly

Set the stream open flag immediately after the
stream is opened to ensure correct closure of
the stream if there is an error condition.

Change-Id: I61faf6ddf99ab504e492a4e37d577b67acf99f09
Signed-off-by: Ben Romberger <bromberg@codeaurora.org>