build: enable -Wextra by default

Change-Id: I1e6783fca6530741bf4b81dd13613a6b4235290a
Refs: #3293
diff --git a/tests/daemon/face/ethernet.t.cpp b/tests/daemon/face/ethernet.t.cpp
index a6faf06..4d6f053 100644
--- a/tests/daemon/face/ethernet.t.cpp
+++ b/tests/daemon/face/ethernet.t.cpp
@@ -201,22 +201,24 @@
   face->onReceiveData.connect([&recDatas] (const Data& d) { recDatas.push_back(d); });
 
   // check that packet data is not accessed if pcap didn't capture anything (caplen == 0)
-  static const pcap_pkthdr header1{};
-  face->processIncomingPacket(&header1, nullptr);
+  static const pcap_pkthdr zeroHeader{};
+  face->processIncomingPacket(&zeroHeader, nullptr);
   BOOST_CHECK_EQUAL(face->getCounters().getNInBytes(), 0);
   BOOST_CHECK_EQUAL(recInterests.size(), 0);
   BOOST_CHECK_EQUAL(recDatas.size(), 0);
 
   // runt frame (too short)
-  static const pcap_pkthdr header2{{}, ethernet::HDR_LEN + 6};
+  pcap_pkthdr runtHeader{};
+  runtHeader.caplen = ethernet::HDR_LEN + 6;
   static const uint8_t packet2[ethernet::HDR_LEN + 6]{};
-  face->processIncomingPacket(&header2, packet2);
+  face->processIncomingPacket(&runtHeader, packet2);
   BOOST_CHECK_EQUAL(face->getCounters().getNInBytes(), 0);
   BOOST_CHECK_EQUAL(recInterests.size(), 0);
   BOOST_CHECK_EQUAL(recDatas.size(), 0);
 
   // valid frame, but TLV block has invalid length
-  static const pcap_pkthdr header3{{}, ethernet::HDR_LEN + ethernet::MIN_DATA_LEN};
+  pcap_pkthdr validHeader{};
+  validHeader.caplen = ethernet::HDR_LEN + ethernet::MIN_DATA_LEN;
   static const uint8_t packet3[ethernet::HDR_LEN + ethernet::MIN_DATA_LEN]{
     0x01, 0x00, 0x5e, 0x00, 0x17, 0xaa, // destination address
     0x02, 0x00, 0x00, 0x00, 0x00, 0x02, // source address
@@ -224,13 +226,12 @@
     tlv::NdnlpData,   // TLV type
     0xfd, 0xff, 0xff  // TLV length (invalid because greater than buffer size)
   };
-  face->processIncomingPacket(&header3, packet3);
+  face->processIncomingPacket(&validHeader, packet3);
   BOOST_CHECK_EQUAL(face->getCounters().getNInBytes(), 0);
   BOOST_CHECK_EQUAL(recInterests.size(), 0);
   BOOST_CHECK_EQUAL(recDatas.size(), 0);
 
   // valid frame, but TLV block has invalid type
-  static const pcap_pkthdr header4{{}, ethernet::HDR_LEN + ethernet::MIN_DATA_LEN};
   static const uint8_t packet4[ethernet::HDR_LEN + ethernet::MIN_DATA_LEN]{
     0x01, 0x00, 0x5e, 0x00, 0x17, 0xaa, // destination address
     0x02, 0x00, 0x00, 0x00, 0x00, 0x02, // source address
@@ -238,13 +239,12 @@
     0x00,             // TLV type (invalid)
     0x00              // TLV length
   };
-  face->processIncomingPacket(&header4, packet4);
+  face->processIncomingPacket(&validHeader, packet4);
   BOOST_CHECK_EQUAL(face->getCounters().getNInBytes(), 2);
   BOOST_CHECK_EQUAL(recInterests.size(), 0);
   BOOST_CHECK_EQUAL(recDatas.size(), 0);
 
   // valid frame and valid NDNLP header, but invalid payload
-  static const pcap_pkthdr header5{{}, ethernet::HDR_LEN + ethernet::MIN_DATA_LEN};
   static const uint8_t packet5[ethernet::HDR_LEN + ethernet::MIN_DATA_LEN]{
     0x01, 0x00, 0x5e, 0x00, 0x17, 0xaa, // destination address
     0x02, 0x00, 0x00, 0x00, 0x00, 0x02, // source address
@@ -256,13 +256,12 @@
     0x00,             // NDN TLV type (invalid)
     0x00              // NDN TLV length
   };
-  face->processIncomingPacket(&header5, packet5);
+  face->processIncomingPacket(&validHeader, packet5);
   BOOST_CHECK_EQUAL(face->getCounters().getNInBytes(), 18);
   BOOST_CHECK_EQUAL(recInterests.size(), 0);
   BOOST_CHECK_EQUAL(recDatas.size(), 0);
 
   // valid frame, valid NDNLP header, and valid NDN (interest) packet
-  static const pcap_pkthdr header6{{}, ethernet::HDR_LEN + ethernet::MIN_DATA_LEN};
   static const uint8_t packet6[ethernet::HDR_LEN + ethernet::MIN_DATA_LEN]{
     0x01, 0x00, 0x5e, 0x00, 0x17, 0xaa, // destination address
     0x02, 0x00, 0x00, 0x00, 0x00, 0x02, // source address
@@ -276,7 +275,7 @@
     0x03, 0x66, 0x6f, 0x6f, 0x0a, 0x04,
     0x03, 0xef, 0xe9, 0x7c
   };
-  face->processIncomingPacket(&header6, packet6);
+  face->processIncomingPacket(&validHeader, packet6);
   BOOST_CHECK_EQUAL(face->getCounters().getNInBytes(), 56);
   BOOST_CHECK_EQUAL(recInterests.size(), 1);
   BOOST_CHECK_EQUAL(recDatas.size(), 0);