net: stmmac: dwmac-sun8i: Variable "val" in function sun8i_dwmac_set_syscon()...

net: stmmac: dwmac-sun8i: Variable "val" in function sun8i_dwmac_set_syscon() could be uninitialized

In function sun8i_dwmac_set_syscon(), local variable "val" could
be uninitialized if function regmap_field_read() returns -EINVAL.
However, it will be used directly in the if statement, which
is potentially unsafe.
Signed-off-by: Yizhuo <yzhai003@ucr.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c

@@ -873,7 +873,12 @@ static int sun8i_dwmac_set_syscon(struct stmmac_priv *priv)
 	int ret;
 	u32 reg, val;
 
-	regmap_field_read(gmac->regmap_field, &val);
+	ret = regmap_field_read(gmac->regmap_field, &val);
+	if (ret) {
+		dev_err(priv->device, "Fail to read from regmap field.\n");
+		return ret;
+	}
+
 	reg = gmac->variant->default_syscon_value;
 	if (reg != val)
 		dev_warn(priv->device,