ASoC: Intel: sst: Fix error-code check in sst_pause_stream()

The value returned by sst_prepare_and_post_msg() is a negated SST_ERR_*
value, so we must check for -SST_ERR_INVALID_STREAM_ID. Note that
sst_pause_resume() already has the correct check.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mark Brown <broonie@kernel.org>