[NET]: Use NIP6_FMT in kernel.h

There are errors and inconsistency in the display of NIP6 strings.
	ie: net/ipv6/ip6_flowlabel.c

There are errors and inconsistency in the display of NIPQUAD strings too.
	ie: net/netfilter/nf_conntrack_ftp.c

This patch:
	adds NIP6_FMT to kernel.h
	changes all code to use NIP6_FMT
	fixes net/ipv6/ip6_flowlabel.c
	adds NIPQUAD_FMT to kernel.h
	fixes net/netfilter/nf_conntrack_ftp.c
	changes a few uses of "%u.%u.%u.%u" to NIPQUAD_FMT for symmetry to NIP6_FMT

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
index 6de8ee1..7b5b94f 100644
--- a/net/ipv6/esp6.c
+++ b/net/ipv6/esp6.c
@@ -266,8 +266,7 @@
 	x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, esph->spi, IPPROTO_ESP, AF_INET6);
 	if (!x)
 		return;
-	printk(KERN_DEBUG "pmtu discovery on SA ESP/%08x/"
-			"%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n", 
+	printk(KERN_DEBUG "pmtu discovery on SA ESP/%08x/" NIP6_FMT "\n", 
 			ntohl(esph->spi), NIP6(iph->daddr));
 	xfrm_state_put(x);
 }