[][kernel][common][eth][Remove the unused variable in the mtk_mac_link_down() function]

[Description]
Remove the unused variable in the mtk_mac_link_down() function.

[Release-log]
N/A


Change-Id: I3ac413431f601ec5d1e1ce8610131aaab3e510eb
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/9657234
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 4b9beec..ef1b5bc 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
@@ -1068,8 +1068,6 @@
 {
 	struct mtk_mac *mac = container_of(config, struct mtk_mac,
 					   phylink_config);
-	struct mtk_eth *eth = mac->hw;
-	unsigned int id;
 	u32 mcr, sts;
 
 	mtk_pse_set_mac_port_link(mac, false, interface);
@@ -1078,8 +1076,6 @@
 		mcr &= ~(MAC_MCR_TX_EN | MAC_MCR_RX_EN | MAC_MCR_FORCE_LINK);
 		mtk_w32(mac->hw, mcr, MTK_MAC_MCR(mac->id));
 	} else if (mac->type == MTK_XGDM_TYPE && mac->id != MTK_GMAC1_ID) {
-		struct mtk_usxgmii_pcs *mpcs;
-
 		mcr = mtk_r32(mac->hw, MTK_XMAC_MCR(mac->id));
 		mcr &= 0xfffffff0;
 		mcr |= XMAC_MCR_TRX_DISABLE;
@@ -1088,9 +1084,6 @@
 		sts = mtk_r32(mac->hw, MTK_XGMAC_STS(mac->id));
 		sts &= ~MTK_XGMAC_FORCE_LINK(mac->id);
 		mtk_w32(mac->hw, sts, MTK_XGMAC_STS(mac->id));
-
-		id = mtk_mac2xgmii_id(eth, mac->id);
-		mpcs = &eth->usxgmii->pcs[id];
 	}
 }