net: abort network initialization if the PHY driver fails

Now that phy_startup() can return an actual error code, check for that error
code and abort network initialization if the PHY fails.

Signed-off-by: Timur Tabi <timur@freescale.com>
Acked-by: Nobuhiro Iwamamatsu <nobuhiro.iwamatsu.yj@renesas.com> (sh_eth part)
Acked-by: Stephan Linz <linz@li-pro.net> (Xilinx part, xilinx_axi_emac and xilinx_ll_temac)
Reviewed-by: Marek Vasut <marex@denx.de> (FEC part)
diff --git a/drivers/net/xilinx_axi_emac.c b/drivers/net/xilinx_axi_emac.c
index 7854a04..d777144 100644
--- a/drivers/net/xilinx_axi_emac.c
+++ b/drivers/net/xilinx_axi_emac.c
@@ -272,7 +272,11 @@
 	phydev->advertising = phydev->supported;
 	priv->phydev = phydev;
 	phy_config(phydev);
-	phy_startup(phydev);
+	if (phy_startup(phydev)) {
+		printf("axiemac: could not initialize PHY %s\n",
+		       phydev->dev->name);
+		return 0;
+	}
 
 	switch (phydev->speed) {
 	case 1000: