spi: spi-fsl-dspi: Reduce indentation in dspi_release_dma()

There is no point in surrounding an entire function block in an if
condition. Rather, exit early if the condition is false.
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://lore.kernel.org/r/20190818180115.31114-7-olteanv@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-fsl-dspi.c

@@ -471,18 +471,19 @@ static void dspi_release_dma(struct fsl_dspi *dspi)
 	struct fsl_dspi_dma *dma = dspi->dma;
 	struct device *dev = &dspi->pdev->dev;
 
-	if (dma) {
-		if (dma->chan_tx) {
-			dma_unmap_single(dev, dma->tx_dma_phys,
-					DSPI_DMA_BUFSIZE, DMA_TO_DEVICE);
-			dma_release_channel(dma->chan_tx);
-		}
+	if (!dma)
+		return;
 
-		if (dma->chan_rx) {
-			dma_unmap_single(dev, dma->rx_dma_phys,
-					DSPI_DMA_BUFSIZE, DMA_FROM_DEVICE);
-			dma_release_channel(dma->chan_rx);
-		}
+	if (dma->chan_tx) {
+		dma_unmap_single(dev, dma->tx_dma_phys,
+				 DSPI_DMA_BUFSIZE, DMA_TO_DEVICE);
+		dma_release_channel(dma->chan_tx);
+	}
+
+	if (dma->chan_rx) {
+		dma_unmap_single(dev, dma->rx_dma_phys,
+				 DSPI_DMA_BUFSIZE, DMA_FROM_DEVICE);
+		dma_release_channel(dma->chan_rx);
 	}
 }