IPSEC: SPD counters in the stats sgement

- return the stats_index of each SPD in the create API call
- no ip_any in the API as this creates 2 SPD entries. client must add both v4 and v6 explicitly
- only one pool of SPD entries (rhter than one per-SPD) to support this
- no packets/bytes in the dump API. Polling the stats segment is much more efficient
  (if the SA lifetime is based on packet/bytes)
- emit the policy index in the packet trace and CLI commands.

Change-Id: I7eaf52c9d0495fa24450facf55229941279b8569
Signed-off-by: Neale Ranns <nranns@cisco.com>
diff --git a/src/vnet/ipsec/ipsec_sa.c b/src/vnet/ipsec/ipsec_sa.c
index a76197b..d439b4d 100644
--- a/src/vnet/ipsec/ipsec_sa.c
+++ b/src/vnet/ipsec/ipsec_sa.c
@@ -86,19 +86,16 @@
 ipsec_is_sa_used (u32 sa_index)
 {
   ipsec_main_t *im = &ipsec_main;
-  ipsec_spd_t *spd;
-  ipsec_policy_t *p;
   ipsec_tunnel_if_t *t;
+  ipsec_policy_t *p;
 
   /* *INDENT-OFF* */
-  pool_foreach(spd, im->spds, ({
-    pool_foreach(p, spd->policies, ({
-      if (p->policy == IPSEC_POLICY_ACTION_PROTECT)
-        {
-          if (p->sa_index == sa_index)
-            return 1;
-        }
-    }));
+  pool_foreach(p, im->policies, ({
+     if (p->policy == IPSEC_POLICY_ACTION_PROTECT)
+       {
+         if (p->sa_index == sa_index)
+           return 1;
+       }
   }));
 
   pool_foreach(t, im->tunnel_interfaces, ({