ASoC: Intel: Delete an unnecessary check before the function call "sst_dma_free"

The sst_dma_free() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/intel/sst-dsp.c

@@ -410,8 +410,7 @@ void sst_dsp_free(struct sst_dsp *sst)
 	if (sst->ops->free)
 		sst->ops->free(sst);
 
-	if (sst->dma)
-		sst_dma_free(sst->dma);
+	sst_dma_free(sst->dma);
 }
 EXPORT_SYMBOL_GPL(sst_dsp_free);