ASoC: Intel: Skylake: Don't return failure on machine driver reload

When we unload and reload machine driver, we shouldn't return that we
failed to initialize. This allows to reload machine driver, without
having to unload whole stack.

Signed-off-by: Amadeusz Sławiński <amadeuszx.slawinski@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>