Fix up USB drivers that return an errno value (result of usb_submit_urb())
to qdisc_restart(), causing qdisc_restart() to print a warning and requeue/
retransmit the skb.

- hso: skb is freed: use after free
- at76_usb: skb is freed: use after free

Compile tested only.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>