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/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 70552c4..00bcb88 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1349,6 +1349,7 @@
 		BUG();
 	}
 	xdst = dst_alloc(dst_ops, NULL, 0, 0, 0);
+	memset(&xdst->u.rt6.rt6i_table, 0, sizeof(*xdst) - sizeof(struct dst_entry));
 	xfrm_policy_put_afinfo(afinfo);
 
 	if (likely(xdst))