asoc: msm-lsm-client: stop lab during lsm close

Buffering is not stopped during lsm close due to
which lab buffers can be queued during teardown of
session. This leads to read being issued even after session
close. Stop lab during close to avoid this. Use correct
return value to indicate errors during lsm start and stop.

Change-Id: I52fa33cebaa3ee6ae60eb2a60bb1e833f2a9d0d6
Signed-off-by: Chaithanya Krishna Bacharaju <chaithan@codeaurora.org>