ipsec: one thread index per-SA

Type: improvement

AN SA is uni-drectional therefore it can be used only for encrypt or
decrypt, not both. So it only needs one thread ID. free up some space on
the 1st cacheline.

Signed-off-by: Neale Ranns <neale@graphiant.com>
Change-Id: I21cb7cff70a763cbe2bffead860b574bc80b3136
diff --git a/src/vnet/ipsec/ipsec_format.c b/src/vnet/ipsec/ipsec_format.c
index 909254a..19321e7 100644
--- a/src/vnet/ipsec/ipsec_format.c
+++ b/src/vnet/ipsec/ipsec_format.c
@@ -293,8 +293,7 @@
 
   s = format (s, "\n   locks %d", sa->node.fn_locks);
   s = format (s, "\n   salt 0x%x", clib_net_to_host_u32 (sa->salt));
-  s = format (s, "\n   thread-indices [encrypt:%d decrypt:%d]",
-	      sa->encrypt_thread_index, sa->decrypt_thread_index);
+  s = format (s, "\n   thread-index:%d", sa->thread_index);
   s = format (s, "\n   seq %u seq-hi %u", sa->seq, sa->seq_hi);
   s = format (s, "\n   last-seq %u last-seq-hi %u window %U",
 	      sa->last_seq, sa->last_seq_hi,