gianfar: Carefully free skbs in functions called by netpoll.

netpoll can call functions in hard irq context that are ordinarily
called in lesser contexts.  For those functions use dev_kfree_skb_any
and dev_consume_skb_any so skbs are freed safely from hard irq
context.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>