net: ethernet: mtk-star-emac: remove unused variable

The desc pointer is set but not used. Remove it.
Reported-by: kbuild test robot <lkp@intel.com>
Fixes: 8c7bd5a4 ("net: ethernet: mtk-star-emac: new driver")
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mediatek/mtk_star_emac.c

@@ -746,15 +746,12 @@ mtk_star_ring_free_skbs(struct mtk_star_priv *priv, struct mtk_star_ring *ring,
 					   struct mtk_star_ring_desc_data *))
 {
 	struct mtk_star_ring_desc_data desc_data;
-	struct mtk_star_ring_desc *desc;
 	int i;
 
 	for (i = 0; i < MTK_STAR_RING_NUM_DESCS; i++) {
 		if (!ring->dma_addrs[i])
 			continue;
 
-		desc = &ring->descs[i];
-
 		desc_data.dma_addr = ring->dma_addrs[i];
 		desc_data.skb = ring->skbs[i];