ASoC: uniphier: fix an error code in uniphier_aio_comprdma_new()

The dma_mapping_error() returns true or false, but we want to return
-ENOMEM if there was an error.

Fixes: e9813122 ("ASoC: uniphier: add support for UniPhier AIO compress audio")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Tested-by: Katsuhiro Suzuki <suzuki.katsuhiro@socionext.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/uniphier/aio-compress.c

@@ -54,12 +54,11 @@ static int uniphier_aio_comprdma_new(struct snd_soc_pcm_runtime *rtd)
 		dma_dir = DMA_TO_DEVICE;
 
 	sub->compr_addr = dma_map_single(dev, sub->compr_area, size, dma_dir);
-	ret = dma_mapping_error(dev, sub->compr_addr);
-	if (ret) {
+	if (dma_mapping_error(dev, sub->compr_addr)) {
 		kfree(sub->compr_area);
 		sub->compr_area = NULL;
 
-		return ret;
+		return -ENOMEM;
 	}
 
 	sub->compr_bytes = size;