MPLS hash function improvements

Change-Id: I28e98f445c01493562b6196a4f5b532a51f178af
Signed-off-by: Neale Ranns <nranns@cisco.com>
diff --git a/src/vnet/dpo/mpls_label_dpo.c b/src/vnet/dpo/mpls_label_dpo.c
index 1847953..1c451a5 100644
--- a/src/vnet/dpo/mpls_label_dpo.c
+++ b/src/vnet/dpo/mpls_label_dpo.c
@@ -356,7 +356,7 @@
                 }
                 if (PREDICT_TRUE(vnet_buffer(b2)->mpls.first))
                 {
-                    ASSERT(2 != vnet_buffer (b2)->mpls.ttl);
+                    ASSERT(1 != vnet_buffer (b2)->mpls.ttl);
 
                     ttl2 = vnet_buffer(b2)->mpls.ttl - 1;
                 }