phy: ocelot-serdes: fix out-of-bounds read

Currently, there is an out-of-bounds read on array ctrl->phys,
once variable i reaches the maximum array size of SERDES_MAX
in the for loop.

Fix this by changing the condition in the for loop from
i <= SERDES_MAX to i < SERDES_MAX.

Addresses-Coverity-ID: 1473966 ("Out-of-bounds read")
Addresses-Coverity-ID: 1473959 ("Out-of-bounds read")
Fixes: 51f6b41 ("phy: add driver for Microsemi Ocelot SerDes muxing")
Reviewed-by: Quentin Schulz <quentin.schulz@bootlin.com>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/phy/mscc/phy-ocelot-serdes.c

@@ -206,7 +206,7 @@ static struct phy *serdes_simple_xlate(struct device *dev,
 	port = args->args[0];
 	idx = args->args[1];
 
-	for (i = 0; i <= SERDES_MAX; i++) {
+	for (i = 0; i < SERDES_MAX; i++) {
 		struct serdes_macro *macro = phy_get_drvdata(ctrl->phys[i]);
 
 		if (idx != macro->idx)
@@ -260,7 +260,7 @@ static int serdes_probe(struct platform_device *pdev)
 	if (IS_ERR(ctrl->regs))
 		return PTR_ERR(ctrl->regs);
 
-	for (i = 0; i <= SERDES_MAX; i++) {
+	for (i = 0; i < SERDES_MAX; i++) {
 		ret = serdes_phy_create(ctrl, i, &ctrl->phys[i]);
 		if (ret)
 			return ret;