polling: remove usage of eventlet.sleep()

In this commit we do replace usage of eventlet.sleep() with
time.sleep(0).

After that we remove monkey patching we should be able to completly
remove this call.

Related-bug: #2087939
Change-Id: If78f84923a8c582cbec14c359ffe7ddf56347733
Signed-off-by: Sahid Orentino Ferdjaoui <sahid.ferdjaoui@industrialdiscipline.com>

neutron/agent/common/polling.py

@@ -14,8 +14,8 @@
 #    under the License.
 
 import contextlib
+import time
 
-import eventlet
 from neutron_lib.plugins.ml2 import ovs_constants as ovs_const
 from oslo_config import cfg
 from oslo_log import log as logging
@@ -71,8 +71,9 @@ class InterfacePollingMinimizer(base_polling.BasePollingManager):
 
     def _is_polling_required(self):
         # Maximize the chances of update detection having a chance to
-        # collect output.
-        eventlet.sleep()
+        # collect output.  TODO(sahid): We can remove this line once
+        # eventlet monkey patching removed.
+        time.sleep(0)
         return self._monitor.has_updates
 
     def get_events(self):