build: stop defining _DEBUG, rely only on NDEBUG instead

NDEBUG is more standard on non-Microsoft platforms, and _DEBUG is
technically a reserved identifier.

Change-Id: I24c951032d50b37853dc1a38ac844b0be5ac8937
diff --git a/daemon/face/lp-reliability.cpp b/daemon/face/lp-reliability.cpp
index 4019902..107212e 100644
--- a/daemon/face/lp-reliability.cpp
+++ b/daemon/face/lp-reliability.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2023,  Regents of the University of California,
+ * Copyright (c) 2014-2024,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -400,21 +400,6 @@
   }
 }
 
-LpReliability::UnackedFrag::UnackedFrag(lp::Packet pkt)
-  : pkt(std::move(pkt))
-  , sendTime(time::steady_clock::now())
-  , retxCount(0)
-  , nGreaterSeqAcks(0)
-{
-}
-
-LpReliability::NetPkt::NetPkt(lp::Packet&& pkt, bool isInterest)
-  : pkt(std::move(pkt))
-  , isInterest(isInterest)
-  , didRetx(false)
-{
-}
-
 std::ostream&
 operator<<(std::ostream& os, const FaceLogHelper<LpReliability>& flh)
 {