ASoC: sigmadsp: Fix missleading return value

Forwarding the return value of i2c_master_send, leads to errors
later on, since i2c_master_send returns the number of bytes
transmittet. Check for ret < 0 instead and return 0 otherwise.
Signed-off-by: Pascal Huerst <pascal.huerst@gmail.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/sigmadsp-i2c.c

@@ -31,7 +31,10 @@ static int sigmadsp_write_i2c(void *control_data,
 
 	kfree(buf);
 
-	return ret;
+	if (ret < 0)
+		return ret;
+
+	return 0;
 }
 
 static int sigmadsp_read_i2c(void *control_data,