atm: unset IFF_XMIT_DST_RELEASE in clip_setup()

clip_start_xmit() needs skb->dst so tell dev_hard_start_xmit()
to no release it.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/atm/clip.c

@@ -557,6 +557,7 @@ static void clip_setup(struct net_device *dev)
 	/* without any more elaborate queuing. 100 is a reasonable */
 	/* compromise between decent burst-tolerance and protection */
 	/* against memory hogs. */
+	dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
 }
 
 static int clip_create(int number)