net: hix5hd2_gmac: Remove unneeded cast from memory allocation

Remove casting the values returned by memory allocation function.

Coccinelle emits WARNING:

./drivers/net/ethernet/hisilicon/hix5hd2_gmac.c:1027:9-23: WARNING:
casting value returned by memory allocation function to (struct sg_desc *) is useless.

This issue was detected by using the Coccinelle software.

Signed-off-by: Wang Hai <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/hisilicon/hix5hd2_gmac.c

···
 	struct sg_desc *desc;
 	dma_addr_t phys_addr;
 
-	desc = (struct sg_desc *)dma_alloc_coherent(priv->dev,
-				TX_DESC_NUM * sizeof(struct sg_desc),
-				&phys_addr, GFP_KERNEL);
+	desc = dma_alloc_coherent(priv->dev,
+				  TX_DESC_NUM * sizeof(struct sg_desc),
+				  &phys_addr, GFP_KERNEL);
 	if (!desc)
 		return -ENOMEM;