ASoC: Intel: Skylake: Fix return for pm_runtime_get_sync()

pm_runtime_get_sync() will return a negative value in case of
error and can return postive value for success.  The return check
for pm_runtime_get_sync() must be less than 0, so fix it

Signed-off-by: Jeeja KP <jeeja.kp@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/intel/skylake/skl-pcm.c

@@ -116,7 +116,7 @@ static int skl_pcm_open(struct snd_pcm_substream *substream,
 
 	dev_dbg(dai->dev, "%s: %s\n", __func__, dai->name);
 	ret = pm_runtime_get_sync(dai->dev);
-	if (ret)
+	if (ret < 0)
 		return ret;
 
 	stream = snd_hdac_ext_stream_assign(ebus, substream,