[VIA_VELOCITY]: Don't oops on MTU change.

Simple mtu change when device is down.
Fix http://bugzilla.kernel.org/show_bug.cgi?id=9382.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/via-velocity.c b/drivers/net/via-velocity.c
index 5c4a92d..450e29d 100644
--- a/drivers/net/via-velocity.c
+++ b/drivers/net/via-velocity.c
@@ -1963,6 +1963,11 @@
 		return -EINVAL;
 	}
 
+	if (!netif_running(dev)) {
+		dev->mtu = new_mtu;
+		return 0;
+	}
+
 	if (new_mtu != oldmtu) {
 		spin_lock_irqsave(&vptr->lock, flags);