PM / AVS: SmartReflex: NULL check before some freeing functions is not needed

NULL check before some freeing functions is not needed.

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>