Check TP type rather than doing a blind cast

Check TP type rather than doing a blind cast

Here we have a blind cast, which does not go through:

[main] WARN org.opendaylight.ovsdb.hwvtepsouthbound.transact.TransactUtils - Failed to add to Transaction Histroy
java.lang.ClassCastException: org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.network.topology.rev131021.network.topology.topology.node.TerminationPoint$$$codecImpl cannot be cast to org.opendaylight.ovsdb.schema.hardwarevtep.PhysicalLocator
	at org.opendaylight.ovsdb.hwvtepsouthbound.transact.TransactUtils.addLocatorToTransactionHistory(TransactUtils.java:270)
	at org.opendaylight.ovsdb.hwvtepsouthbound.transact.TransactUtils.createPhysicalLocatorSet(TransactUtils.java:139)
	at org.opendaylight.ovsdb.hwvtepsouthbound.transact.McastMacsRemoteUpdateCommand.setLocatorSet(McastMacsRemoteUpdateCommand.java:135)
	at org.opendaylight.ovsdb.hwvtepsouthbound.transact.McastMacsRemoteUpdateCommand.doDeviceTransaction(McastMacsRemoteUpdateCommand.java:93)
	at org.opendaylight.ovsdb.hwvtepsouthbound.transact.McastMacsRemoteUpdateCommand.doDeviceTransaction(McastMacsRemoteUpdateCommand.java:1)
	at org.opendaylight.ovsdb.hwvtepsouthbound.transact.AbstractTransactCommand.processDependencies(AbstractTransactCommand.java:125)
	at org.opendaylight.ovsdb.hwvtepsouthbound.transact.McastMacsRemoteUpdateCommand.onConfigUpdate(McastMacsRemoteUpdateCommand.java:78)
	at org.opendaylight.ovsdb.hwvtepsouthbound.transact.McastMacsRemoteUpdateCommand.updateMcastMacRemote(McastMacsRemoteUpdateCommand.java:65)
	at org.opendaylight.ovsdb.hwvtepsouthbound.transact.McastMacsRemoteUpdateCommand.execute(McastMacsRemoteUpdateCommand.java:55)
	at org.opendaylight.ovsdb.hwvtepsouthbound.transact.TransactCommandAggregator.execute(TransactCommandAggregator.java:73)
	at org.opendaylight.ovsdb.hwvtepsouthbound.transact.TransactInvokerImpl.invoke(TransactInvokerImpl.java:41)
	at org.opendaylight.ovsdb.hwvtepsouthbound.HwvtepConnectionInstance.transact(HwvtepConnectionInstance.java:132)
	at org.opendaylight.ovsdb.hwvtepsouthbound.HwvtepConnectionInstance.transact(HwvtepConnectionInstance.java:104)
	at org.opendaylight.ovsdb.hwvtepsouthbound.HwvtepDataChangeListener.updateData(HwvtepDataChangeListener.java:178)
	at org.opendaylight.ovsdb.hwvtepsouthbound.HwvtepDataChangeListener.onDataTreeChanged(HwvtepDataChangeListener.java:81)
	at org.opendaylight.controller.md.sal.binding.impl.BindingDOMDataTreeChangeListenerAdapter.onDataTreeChanged(BindingDOMDataTreeChangeListenerAdapter.java:43)

Rather than incurring this, perform an instanceof check and debug
ignored data.

Change-Id: Icc3d1abe5afd2b9b60c7632606551904b7d27af7
Signed-off-by: Robert Varga <robert.varga@pantheon.tech>