session: use session error type instead of vnet error

Type: improvement

Change-Id: Ie0bad9e03ac2e29da23af01ee7f63cb44489ad9c
Signed-off-by: Filip Tehlar <ftehlar@cisco.com>
diff --git a/src/vnet/session/session_lookup.h b/src/vnet/session/session_lookup.h
index c1037df..86148d1 100644
--- a/src/vnet/session/session_lookup.h
+++ b/src/vnet/session/session_lookup.h
@@ -130,7 +130,7 @@
   u8 transport_proto;
 } session_rule_add_del_args_t;
 
-int vnet_session_rule_add_del (session_rule_add_del_args_t * args);
+session_error_t vnet_session_rule_add_del (session_rule_add_del_args_t *args);
 void session_lookup_set_tables_appns (app_namespace_t * app_ns);
 
 void session_lookup_init (void);