loci: replace validator with a stub

The negative unit tests are commented out since the stub validator doesn't do
anything.
diff --git a/c_gen/templates/locitest/test_validator.c b/c_gen/templates/locitest/test_validator.c
index a4b55eb..858ec4f 100644
--- a/c_gen/templates/locitest/test_validator.c
+++ b/c_gen/templates/locitest/test_validator.c
@@ -49,8 +49,10 @@
 
     TEST_ASSERT(of_validate_message(msg, of_message_length_get(msg)) == 0);
 
+#if 0
     of_message_length_set(msg, of_message_length_get(msg) - 1);
     TEST_ASSERT(of_validate_message(msg, of_message_length_get(msg)) == -1);
+#endif
 
     of_table_stats_request_delete(obj);
     return TEST_PASS;
@@ -71,8 +73,10 @@
 
     TEST_ASSERT(of_validate_message(msg, of_message_length_get(msg)) == 0);
 
+#if 0
     of_message_length_set(msg, of_message_length_get(msg) - 1);
     TEST_ASSERT(of_validate_message(msg, of_message_length_get(msg)) == -1);
+#endif
 
     of_table_stats_reply_delete(obj);
     return TEST_PASS;
@@ -95,11 +99,13 @@
 
     TEST_ASSERT(of_validate_message(msg, of_message_length_get(msg)) == 0);
 
+#if 0
     of_message_length_set(msg, of_message_length_get(msg) - 1);
     TEST_ASSERT(of_validate_message(msg, of_message_length_get(msg)) == -1);
 
     of_message_length_set(msg, of_message_length_get(msg) + 2);
     TEST_ASSERT(of_validate_message(msg, of_message_length_get(msg)) == -1);
+#endif
 
     of_flow_modify_delete(obj);
     return TEST_PASS;