spi: sh-msiof: Fix transmit-only DMA transfers

Fix tx/rx mixup, which broke transmit-only transfers.

Introduced by commit 4240305f7cbdc7782aa8bc40cc702775d9ac0839
("spi: sh-msiof: Fix leaking of unused DMA descriptors").
Reported-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

drivers/spi/spi-sh-msiof.c

@@ -689,9 +689,9 @@ static int sh_msiof_dma_once(struct sh_msiof_spi_priv *p, const void *tx,
 	reinit_completion(&p->done);
 
 	/* Now start DMA */
-	if (tx)
-		dma_async_issue_pending(p->master->dma_rx);
 	if (rx)
+		dma_async_issue_pending(p->master->dma_rx);
+	if (tx)
 		dma_async_issue_pending(p->master->dma_tx);
 
 	ret = sh_msiof_spi_start(p, rx);