ipsec: Use .api declared error counters

Type: improvement

Signed-off-by: Neale Ranns <neale@graphiant.com>
Change-Id: Ica7de5a493389c6f53b7cf04e06939473a63d2b9
diff --git a/test/test_ipsec_tun_if_esp.py b/test/test_ipsec_tun_if_esp.py
index 9da75f0..d10ad21 100644
--- a/test/test_ipsec_tun_if_esp.py
+++ b/test/test_ipsec_tun_if_esp.py
@@ -1842,7 +1842,7 @@
             dst=self.pg1.remote_ip6,
         )
         self.send_and_assert_no_replies(self.tun_if, tx)
-        node_name = "/err/%s/unsupported payload" % self.tun4_decrypt_node_name[0]
+        node_name = "/err/%s/unsup_payload" % self.tun4_decrypt_node_name[0]
         self.assertEqual(1, self.statistics.get_err_counter(node_name))
 
 
@@ -2577,9 +2577,7 @@
         # bounce the interface state
         p.tun_if.admin_down()
         self.verify_drop_tun_66(np, count=127)
-        node = (
-            "/err/ipsec6-tun-input/%s" % "ipsec packets received on disabled interface"
-        )
+        node = "/err/ipsec6-tun-input/disabled"
         self.assertEqual(127, self.statistics.get_err_counter(node))
         p.tun_if.admin_up()
         self.verify_tun_66(np, count=127)