Composite next hop for mirror destination is having zero component

next hops this because of passing incorrect vm interface mac address
for component next hop key construction.

Fix: derive mac address key from vm_mac() method which is used for
creating interface next hops .

Change-Id: Ic0d0a70903ae3e70a746b81f46d7a1c61f9de51e
Closes-Bug: #1786487

src/vnsw/agent/oper/vxlan.cc

@@ -67,7 +67,7 @@ void VxLanTable::VmInterfaceNotify(DBTablePartBase *partition, DBEntryBase *e) {
 
     ComponentNHKeyPtr nh_key(new ComponentNHKey(vm_itf->label(),vm_itf->GetUuid(),
                                                 InterfaceNHFlags::BRIDGE,
-                                                vm_itf->mac()));
+                                                vm_itf->vm_mac()));
     // if the interface deleted remove the entry from map
     // else add it to composite NH list
     if (intf->IsDeleted() || ((vm_itf->l2_active() == false) &&