tests: tag the tests that do not work with multi-worker configuration

If the multi-worker default VPP configuration is triggered by
setting VPP_WORKER_CONFIG="workers 2", some of the tests fail
for various reasons.

It's a substantial number, so this change marks all of the
testsets that have this issue, such that they can be addressed
later independently.

Type: test
Change-Id: I4f77196499edef3300afe7eabef9cbff91f794d3
Signed-off-by: Andrew Yourtchenko <ayourtch@gmail.com>
diff --git a/test/test_neighbor.py b/test/test_neighbor.py
index f69a263..c34ac1a 100644
--- a/test/test_neighbor.py
+++ b/test/test_neighbor.py
@@ -4,6 +4,7 @@
 import os
 from socket import AF_INET, AF_INET6, inet_pton
 
+from framework import tag_fixme_vpp_workers
 from framework import VppTestCase, VppTestRunner
 from vpp_neighbor import VppNeighbor, find_nbr
 from vpp_ip_route import VppIpRoute, VppRoutePath, find_route, \
@@ -1815,6 +1816,7 @@
         conn2.remove_vpp_config()
 
 
+@tag_fixme_vpp_workers
 class NeighborStatsTestCase(VppTestCase):
     """ ARP/ND Counters """