net: sparx5: Do not use mac_addr uninitialized in mchp_sparx5_probe()

Clang warns:

drivers/net/ethernet/microchip/sparx5/sparx5_main.c:760:29: warning:
variable 'mac_addr' is uninitialized when used here [-Wuninitialized]
        if (of_get_mac_address(np, mac_addr)) {
                                   ^~~~~~~~
drivers/net/ethernet/microchip/sparx5/sparx5_main.c:669:14: note:
initialize the variable 'mac_addr' to silence this warning
        u8 *mac_addr;
                    ^
                     = NULL
1 warning generated.

mac_addr is only used to store the value retrieved from
of_get_mac_address(), which is then copied into the base_mac member of
the sparx5 struct using ether_addr_copy(). It is easier to just use the
base_mac address directly, which avoids the warning and the extra copy.

Fixes: 3cfa11b ("net: sparx5: add the basic sparx5 driver")
Link: ClangBuiltLinux#1413
Signed-off-by: Nathan Chancellor <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: nathanchance

drivers/net/ethernet/microchip/sparx5/sparx5_main.c

@@ -670,7 +670,6 @@ static int mchp_sparx5_probe(struct platform_device *pdev)
 	struct reset_control *reset;
 	struct sparx5 *sparx5;
 	int idx = 0, err = 0;
-	u8 *mac_addr;
 
 	if (!np && !pdev->dev.platform_data)
 		return -ENODEV;
@@ -761,12 +760,10 @@ static int mchp_sparx5_probe(struct platform_device *pdev)
 	if (err)
 		goto cleanup_config;
 
-	if (of_get_mac_address(np, mac_addr)) {
+	if (!of_get_mac_address(np, sparx5->base_mac)) {
 		dev_info(sparx5->dev, "MAC addr was not set, use random MAC\n");
 		eth_random_addr(sparx5->base_mac);
 		sparx5->base_mac[5] = 0;
-	} else {
-		ether_addr_copy(sparx5->base_mac, mac_addr);
 	}
 
 	sparx5->xtr_irq = platform_get_irq_byname(sparx5->pdev, "xtr");