spi: davinci: use dma_mapping_error()

The correct error checking for dma_map_single() is to use
dma_mapping_error().
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-davinci.c

@@ -646,7 +646,7 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
 			buf = t->rx_buf;
 		t->rx_dma = dma_map_single(&spi->dev, buf,
 				t->len, DMA_FROM_DEVICE);
-		if (!t->rx_dma) {
+		if (dma_mapping_error(&spi->dev, !t->rx_dma)) {
 			ret = -EFAULT;
 			goto err_rx_map;
 		}
@@ -660,7 +660,7 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
 			buf = (void *)t->tx_buf;
 		t->tx_dma = dma_map_single(&spi->dev, buf,
 				t->len, DMA_TO_DEVICE);
-		if (!t->tx_dma) {
+		if (dma_mapping_error(&spi->dev, t->tx_dma)) {
 			ret = -EFAULT;
 			goto err_tx_map;
 		}