realtek: ethernet: avoid using unitialized memory

The mac_addr variable was not zero-initialized, causing weird side effects
when the memory contents were a valid MAC address.

Signed-off-by: Carl-Daniel Hailfinger <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/21504
Signed-off-by: Stijn Tintel <[email protected]>
(cherry picked from commit 19b8d391a95d5a2fa038551a9498a9fd426dfc0e)

target/linux/realtek/files-6.12/drivers/net/ethernet/rtl838x_eth.c

@@ -1650,7 +1650,7 @@ static int __init rtl838x_eth_probe(struct platform_device *pdev)
 	struct resource *res, *mem;
 	phy_interface_t phy_mode;
 	struct phylink *phylink;
-	u8 mac_addr[ETH_ALEN];
+	u8 mac_addr[ETH_ALEN] = {0};
 	int err = 0, rxrings, rxringlen;
 	struct ring_b *ring;