DMA: sudmac: fix compiler warning

Fix the following compiler warning:

drivers/dma/sh/sudmac.c: In function 'sudmac_chan_remove':
drivers/dma/sh/sudmac.c:302: warning: unused variable 'sc'
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/sh/sudmac.c

@@ -298,8 +298,6 @@ static void sudmac_chan_remove(struct sudmac_device *su_dev)
 	int i;
 
 	shdma_for_each_chan(schan, &su_dev->shdma_dev, i) {
-		struct sudmac_chan *sc = to_chan(schan);
-
 		BUG_ON(!schan);
 
 		shdma_chan_remove(schan);