ASoC: Intel: Skylake: Fix uninitialized return

On failure to get dsp_ops, dsp_init returns error without assigning ret. ret
is assigned in code path which will never be executed. Fix it.

Fixes: f77d443c ("ASoC: Intel: Skylake: Fix to free resources for dsp_init failure"
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Subhransu S. Prusty <subhransu.s.prusty@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>