Starting driver with link down should be ok, it is with every
other driver. So just allow it.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

---
 lib/librte_pmd_virtio/virtio_ethdev.c |    6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

--- a/lib/librte_pmd_virtio/virtio_ethdev.c	2014-08-25 19:00:05.498525861 -0700
+++ b/lib/librte_pmd_virtio/virtio_ethdev.c	2014-08-25 19:00:05.494525839 -0700
@@ -969,14 +969,12 @@ virtio_dev_start(struct rte_eth_dev *dev
 		vtpci_read_dev_config(hw,
 				offsetof(struct virtio_net_config, status),
 				&status, sizeof(status));
-		if ((status & VIRTIO_NET_S_LINK_UP) == 0) {
+		if ((status & VIRTIO_NET_S_LINK_UP) == 0)
 			PMD_INIT_LOG(ERR, "Port: %d Link is DOWN",
 				     dev->data->port_id);
-			return -EIO;
-		} else {
+		else
 			PMD_INIT_LOG(DEBUG, "Port: %d Link is UP",
 				     dev->data->port_id);
-		}
 	}
 	vtpci_reinit_complete(hw);