[][kernel][common][eth][Fix issues detected by Coverity scan]

[Description]
Fix issues detected by Coverity scan.
mtk_rx_alloc: OVERFLOW_BEFORE_WIDEN

[Release-log]
N/A


Change-Id: I887fd79b7cc8fd7c660dbc95ecb2ec92a1e147b7
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/8891297
diff --git a/21.02/files/target/linux/mediatek/files-5.4/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/21.02/files/target/linux/mediatek/files-5.4/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 7c29375..126f284 100644
--- a/21.02/files/target/linux/mediatek/files-5.4/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/21.02/files/target/linux/mediatek/files-5.4/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -2981,7 +2981,7 @@
 		ring->dma = tx_ring->dma + soc->txrx.tx_dma_size *
 			    eth->soc->txrx.txd_size * (ring_no + 1);
 		ring->phys = tx_ring->phys + soc->txrx.tx_dma_size *
-			     eth->soc->txrx.txd_size * (ring_no + 1);
+			     (dma_addr_t)eth->soc->txrx.txd_size * (ring_no + 1);
 	}
 
 	if (!ring->dma)