ASoC: qdsp6: q6asm-dai: clean up a return

Smatch complains that if both "psubstream" and "csubstream" are NULL
then "ret" is uninitialized.  That probably can't happen, but it's
cleaner to just return zero anyway so let's do that.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/sound/soc/qcom/qdsp6/q6asm-dai.c b/sound/soc/qcom/qdsp6/q6asm-dai.c
index 9db9a29..c75fab3 100644
--- a/sound/soc/qcom/qdsp6/q6asm-dai.c
+++ b/sound/soc/qcom/qdsp6/q6asm-dai.c
@@ -493,7 +493,7 @@
 		}
 	}
 
-	return ret;
+	return 0;
 }
 
 static void q6asm_dai_pcm_free(struct snd_pcm *pcm)