net: au1000_eth: fix PHY detection

Commit 7f854420
("phy: Add API for {un}registering an mdio device to a bus.")
broke PHY detection on this driver with a copy-paste bug:
The code is looking 32 times for a PHY at address 0.

Fixes ethernet on AMD DB1100/DB1500/DB1550 boards which have
their (autodetected) PHYs at address 31.

Cc: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/amd/au1000_eth.c

@@ -508,13 +508,12 @@ static int au1000_mii_probe(struct net_device *dev)
 	/* find the first (lowest address) PHY
 	 * on the current MAC's MII bus
 	 */
-	for (phy_addr = 0; phy_addr < PHY_MAX_ADDR; phy_addr++)
-		if (mdiobus_get_phy(aup->mii_bus, aup->phy_addr)) {
-			phydev = mdiobus_get_phy(aup->mii_bus, aup->phy_addr);
-			if (!aup->phy_search_highest_addr)
-				/* break out with first one found */
-				break;
-		}
+	for (phy_addr = 0; phy_addr < PHY_MAX_ADDR; phy_addr++) {
+		phydev = mdiobus_get_phy(aup->mii_bus, phy_addr);
+		if (phydev && !aup->phy_search_highest_addr)
+			/* break out with first one found */
+			break;
+	}
 
 	if (aup->phy1_search_mac0) {
 		/* try harder to find a PHY */