net: of_mdio: use int type for address variable

Use int rather than u32 to fix the following warning:

drivers/of/of_mdio.c:147 of_mdiobus_register() warn: unsigned 'addr' is
never less than zero.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Fixes: 8f83828 ("net: of_mdio: factor out code to parse a phy's 'reg' property")
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/of/of_mdio.c

@@ -121,9 +121,8 @@ int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
 {
 	struct device_node *child;
 	const __be32 *paddr;
-	u32 addr;
 	bool scanphys = false;
-	int rc, i;
+	int addr, rc, i;
 
 	/* Mask out all PHYs from auto probing.  Instead the PHYs listed in
 	 * the device tree are populated after the bus has been registered */