nfs4: Clear PeerAddress before attempting to get local address

If PeerAddress is cleared before invoking GetLocalAddress() we make sure
it won't contain any garbage data in a very unlike case when getsockname()
fails.

src/add-ons/kernel/file_systems/nfs4/RPCCallbackServer.h

@@ -87,6 +87,8 @@ CallbackServer::LocalID()
 	PeerAddress address;
 
 	ASSERT(fListener != NULL);
+
+	memset(&address, 0, sizeof(address));
 	fListener->GetLocalAddress(&address);
 	return address;
 }