ibmveth: Return -EINVAL on all ->probe errors

We had a few cases where we returned success on error.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Santiago Leon <santil@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ibmveth.c b/drivers/net/ibmveth.c
index 8adfff55..11086db 100644
--- a/drivers/net/ibmveth.c
+++ b/drivers/net/ibmveth.c
@@ -1392,7 +1392,7 @@
 							NULL);
 	if (!mac_addr_p) {
 		dev_err(&dev->dev, "Can't find VETH_MAC_ADDR attribute\n");
-		return 0;
+		return -EINVAL;
 	}
 
 	mcastFilterSize_p = (unsigned int *)vio_get_attribute(dev,
@@ -1400,7 +1400,7 @@
 	if (!mcastFilterSize_p) {
 		dev_err(&dev->dev, "Can't find VETH_MCAST_FILTER_SIZE "
 			"attribute\n");
-		return 0;
+		return -EINVAL;
 	}
 
 	netdev = alloc_etherdev(sizeof(struct ibmveth_adapter));