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

[Description]
Fix issues detected by Coverity scan.

1.mtk_probe: NULL_RETURNS
2.mtk_probe: CERT EXP34-C

[Release-log]
N/A


Change-Id: I5e2c2da3c0f06de08aeac81206ab48cbb9706ce5
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/8856903
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 2af1400..2d82d98 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
@@ -5467,6 +5467,8 @@
 		return -ENOMEM;
 
 	eth->soc = of_device_get_match_data(&pdev->dev);
+	if (!eth->soc)
+		return -EINVAL;
 
 	eth->dev = &pdev->dev;
 	eth->dma_dev = &pdev->dev;