ip: remove unused function prototype

ip_do_nat() function was removed prior to kernel 3.4. Remove the
unnecessary function prototype as well.

Reported-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Andy Zhou <azhou@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 file changed