ASoC: tas6424: Save last fault register even when clear

When there is no fault bit set in a fault register we skip the fault
reporting section for that register. This also skips over saving that
registers value. We save the value so we will not double report an
error, but if an error clears then returns we will also not report it
as we did not save the all cleared register value. Fix this by saving
the fault register value in the all clear path.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org