ot1200: Fix the error handling in board_eth_init()

We should not return 0 on failure, so return a negative error code
instead.

Also centralize the error path so that is easier to follow.

Cc: Christian Gmeiner <christian.gmeiner@gmail.com>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
diff --git a/board/bachmann/ot1200/ot1200.c b/board/bachmann/ot1200/ot1200.c
index 2237b7a..eeced79 100644
--- a/board/bachmann/ot1200/ot1200.c
+++ b/board/bachmann/ot1200/ot1200.c
@@ -305,13 +305,13 @@
 
 	bus = fec_get_miibus(base, -1);
 	if (!bus)
-		return 0;
+		return -EINVAL;
 
 	/* scan phy 0 and 5 */
 	phydev = phy_find_by_mask(bus, 0x21, PHY_INTERFACE_MODE_RGMII);
 	if (!phydev) {
-		free(bus);
-		return 0;
+		ret = -EINVAL;
+		goto free_bus;
 	}
 
 	/* depending on the phy address we can detect our board version */
@@ -322,12 +322,16 @@
 
 	printf("using phy at %d\n", phydev->addr);
 	ret = fec_probe(bis, -1, base, bus, phydev);
-	if (ret) {
-		printf("FEC MXC: %s:failed\n", __func__);
-		free(phydev);
-		free(bus);
-	}
+	if (ret)
+		goto free_phydev;
+
 	return 0;
+
+free_phydev:
+	free(phydev);
+free_bus:
+	free(bus);
+	return ret;
 }
 
 int board_init(void)