mmc: sh_mmcif: Correct TX DMA channel allocation

Commit 27cbd7e8 ("mmc: sh_mmcif: rework dma channel handling")
introduced a typo causing the TX DMA channel allocation to be overwritten
by the requested RX DMA channel.

Fixes: 27cbd7e8 ("mmc: sh_mmcif: rework dma channel handling")
Signed-off-by: Chris Paterson <chris.paterson2@renesas.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sh_mmcif.c

@@ -445,7 +445,7 @@ static void sh_mmcif_request_dma(struct sh_mmcif_host *host)
 							pdata->slave_id_rx);
 	} else {
 		host->chan_tx = dma_request_slave_channel(dev, "tx");
-		host->chan_tx = dma_request_slave_channel(dev, "rx");
+		host->chan_rx = dma_request_slave_channel(dev, "rx");
 	}
 	dev_dbg(dev, "%s: got channel TX %p RX %p\n", __func__, host->chan_tx,
 		host->chan_rx);