net: Use non-zero allocations in dst_alloc().

Make dst_alloc() and it's users explicitly initialize the entire
entry.

The zero'ing done by kmem_cache_zalloc() was almost entirely
redundant.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c
index f489b08..74544bc 100644
--- a/net/decnet/dn_route.c
+++ b/net/decnet/dn_route.c
@@ -1129,6 +1129,7 @@
 	if (rt == NULL)
 		goto e_nobufs;
 
+	memset(&rt->fld, 0, sizeof(rt->fld));
 	rt->fld.saddr        = oldflp->saddr;
 	rt->fld.daddr        = oldflp->daddr;
 	rt->fld.flowidn_oif  = oldflp->flowidn_oif;
@@ -1398,6 +1399,7 @@
 	if (rt == NULL)
 		goto e_nobufs;
 
+	memset(&rt->fld, 0, sizeof(rt->fld));
 	rt->rt_saddr      = fld.saddr;
 	rt->rt_daddr      = fld.daddr;
 	rt->rt_gateway    = fld.daddr;