bridge: reset IPCB in br_parse_ip_options

Commit 462fb2af9788a82 (bridge : Sanitize skb before it enters the IP
stack), missed one IPCB init before calling ip_options_compile()

Thanks to Scot Doyle for his tests and bug reports.

Reported-by: Scot Doyle <lkml@scotdoyle.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Hiroaki SHIMODA <shimoda.hiroaki@gmail.com>
Acked-by: Bandan Das <bandan.das@stratus.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Cc: Jan Lübbe <jluebbe@debian.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
int nf_bridge_copy_header(struct sk_buff *skb)
{
	int err;
	unsigned int header_size;

	nf_bridge_update_protocol(skb);
	header_size = ETH_HLEN + nf_bridge_encap_header_len(skb);
	err = skb_cow_head(skb, header_size);
	if (err)
		return err;

	skb_copy_to_linear_data_offset(skb, -header_size,
				       skb->nf_bridge->data, header_size);
	__skb_push(skb, nf_bridge_encap_header_len(skb));
	return 0;
}

int nf_bridge_copy_header(struct sk_buff *skb)
{
	int err;
	unsigned int header_size;

	nf_bridge_update_protocol(skb);
	header_size = ETH_HLEN + nf_bridge_encap_header_len(skb);
	err = skb_cow_head(skb, header_size);
	if (err)
		return err;

	skb_copy_to_linear_data_offset(skb, -header_size,
				       skb->nf_bridge->data, header_size);
	__skb_push(skb, nf_bridge_encap_header_len(skb));
	return 0;
}
