netfilter: nf_conntrack: padding breaks conntrack hash on ARM

commit 0794935e "[NETFILTER]: nf_conntrack: optimize hash_conntrack()"
results in ARM platforms hashing uninitialised padding.  This padding
doesn't exist on other architectures.

Fix this by replacing NF_CT_TUPLE_U_BLANK() with memset() to ensure
everything is initialised.  There were only 4 bytes that
NF_CT_TUPLE_U_BLANK() wasn't clearing anyway (or 12 bytes on ARM).

Signed-off-by: Philip Craig <philipc@snapgear.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 4eac65c..c4b1799 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -104,7 +104,7 @@
 		const struct nf_conntrack_l3proto *l3proto,
 		const struct nf_conntrack_l4proto *l4proto)
 {
-	NF_CT_TUPLE_U_BLANK(tuple);
+	memset(tuple, 0, sizeof(*tuple));
 
 	tuple->src.l3num = l3num;
 	if (l3proto->pkt_to_tuple(skb, nhoff, tuple) == 0)
@@ -151,7 +151,7 @@
 		   const struct nf_conntrack_l3proto *l3proto,
 		   const struct nf_conntrack_l4proto *l4proto)
 {
-	NF_CT_TUPLE_U_BLANK(inverse);
+	memset(inverse, 0, sizeof(*inverse));
 
 	inverse->src.l3num = orig->src.l3num;
 	if (l3proto->invert_tuple(inverse, orig) == 0)