ATM: solos-pci, remove use after free

Stanse found we do in console_show:
  kfree_skb(skb);
  return skb->len;
which is not good. Fix that by remembering the len and use it in the
function instead.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Chas Williams <chas@cmf.nrl.navy.mil>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>