Get rid of custom wrap_db_retry call in sync_allocations

Just for consistency, get rid of the last direct call to
wrap_db_retry and instead use neutron.db.api.retry_db_errors
in the sync_allocations code so we don't potentially get
bitten by slight inconsistencies between the two.

TrivialFix
Related-Bug: #1673243

Change-Id: I975c7d0ec84698d277acbbec6d9cfec5c03439aa

neutron/plugins/ml2/drivers/type_tunnel.py

@@ -20,7 +20,6 @@ import netaddr
 from neutron_lib import context
 from neutron_lib import exceptions as exc
 from oslo_config import cfg
-from oslo_db import api as oslo_db_api
 from oslo_db import exception as db_exc
 from oslo_log import log
 import six
@@ -136,9 +135,7 @@ class _TunnelTypeDriverBase(helpers.SegmentTypeDriver):
         LOG.info(_LI("%(type)s ID ranges: %(range)s"),
                  {'type': self.get_type(), 'range': current_range})
 
-    @oslo_db_api.wrap_db_retry(
-        max_retries=db_api.MAX_RETRIES,
-        exception_checker=db_api.is_retriable)
+    @db_api.retry_db_errors
     def sync_allocations(self):
         # determine current configured allocatable tunnel ids
         tunnel_ids = set()