tqma6_mba6: 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: Markus Niebel <Markus.Niebel@tq-group.com>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
diff --git a/board/tqc/tqma6/tqma6_mba6.c b/board/tqc/tqma6/tqma6_mba6.c
index 6f4cffd..e58b714 100644
--- a/board/tqc/tqma6/tqma6_mba6.c
+++ b/board/tqc/tqma6/tqma6_mba6.c
@@ -309,24 +309,26 @@
 
 	bus = fec_get_miibus(base, -1);
 	if (!bus)
-		return 0;
+		return -EINVAL;
 	/* scan phy */
 	phydev = phy_find_by_mask(bus, (0xf << CONFIG_FEC_MXC_PHYADDR),
 					PHY_INTERFACE_MODE_RGMII);
 
 	if (!phydev) {
-		free(bus);
-		puts("No phy found\n");
-		return 0;
+		ret = -EINVAL;
+		goto free_bus;
 	}
 	ret  = fec_probe(bis, -1, base, bus, phydev);
-	if (ret) {
-		puts("FEC MXC: probe failed\n");
-		free(phydev);
-		free(bus);
-	}
+	if (ret)
+		goto free_phydev;
 
 	return 0;
+
+free_phydev:
+	free(phydev);
+free_bus:
+	free(bus);
+	return ret;
 }
 
 int tqma6_bb_board_early_init_f(void)