stmmac: handle allocation errors in setup functions

If the allocations fail in either dwmac1000_setup() or dwmac100_setup()
then return NULL.  These are called from stmmac_mac_device_setup().  The
check for NULL returns in stmmac_mac_device_setup() needed to be moved
forward a couple lines.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/stmmac/stmmac_main.c b/drivers/net/stmmac/stmmac_main.c
index acf0616..0bdd332 100644
--- a/drivers/net/stmmac/stmmac_main.c
+++ b/drivers/net/stmmac/stmmac_main.c
@@ -1558,15 +1558,15 @@
 	else
 		device = dwmac100_setup(ioaddr);
 
+	if (!device)
+		return -ENOMEM;
+
 	if (priv->enh_desc) {
 		device->desc = &enh_desc_ops;
 		pr_info("\tEnhanced descriptor structure\n");
 	} else
 		device->desc = &ndesc_ops;
 
-	if (!device)
-		return -ENOMEM;
-
 	priv->hw = device;
 
 	priv->wolenabled = priv->hw->pmt;	/* PMT supported */