dmaengine: tegra: make byte counters unsigned int

The buffer byte request length and counter are declared as signed integers
but the values should never be below zero, so make these unsigned integers
instead.
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/tegra20-apb-dma.c

@@ -155,7 +155,7 @@ struct tegra_dma_channel_regs {
  */
 struct tegra_dma_sg_req {
 	struct tegra_dma_channel_regs	ch_regs;
-	int				req_len;
+	unsigned int			req_len;
 	bool				configured;
 	bool				last_sg;
 	struct list_head		node;
@@ -169,8 +169,8 @@ struct tegra_dma_sg_req {
  */
 struct tegra_dma_desc {
 	struct dma_async_tx_descriptor	txd;
-	int				bytes_requested;
-	int				bytes_transferred;
+	unsigned int			bytes_requested;
+	unsigned int			bytes_transferred;
 	enum dma_status			dma_status;
 	struct list_head		node;
 	struct list_head		tx_list;