Clear state on VRF entry only on the VRF delete notify.

The VRF state set by arp proto is being deleted upon ARP entry
deletion, if VRF is delete marked. If the VRF delete notification
comes later, as the state is already cleared, the rest of cleanup
is skipped. The VRF state should be cleared only on VRF delete
notification.

Change-Id: I8a0ae368e4964f54d7a8a5048b9913944ba2c987
closes-bug: 1538789

src/vnsw/agent/services/arp_proto.cc

@@ -500,7 +500,6 @@ ArpProto::ArpIterator
 ArpProto::DeleteArpEntry(ArpProto::ArpIterator iter) {
     ArpEntry *entry = iter->second;
     arp_cache_.erase(iter++);
-    ValidateAndClearVrfState(const_cast<VrfEntry *>(entry->key().vrf));
     delete entry;
     return iter;
 }