[IPV4]: Debug cleanup

Here's a small patch to cleanup NETDEBUG() use in net/ipv4/ for Linux 
kernel 2.6.13-rc5. Also weird use of indentation is changed in some
places.

Signed-off-by: Heikki Orsila <heikki.orsila@iki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>