build+face: Fixing regression that broke ethernet support

As of this commit, libpcap is required unless specifically disabled
using --without-libpcap parameter during configure stage.

Change-Id: Iec6f8bd9babfe4da193c98a49043b08319311106
Refs: #1472
diff --git a/daemon/core/face-uri.cpp b/daemon/core/face-uri.cpp
index 5cfaf72..c9ec548 100644
--- a/daemon/core/face-uri.cpp
+++ b/daemon/core/face-uri.cpp
@@ -25,9 +25,9 @@
 #include "face-uri.hpp"
 #include "core/logger.hpp"
 
-#ifdef HAVE_PCAP
+#ifdef HAVE_LIBPCAP
 #include "face/ethernet.hpp"
-#endif // HAVE_PCAP
+#endif // HAVE_LIBPCAP
 
 #include <boost/regex.hpp>
 
@@ -130,14 +130,14 @@
   return uri;
 }
 
-#ifdef HAVE_PCAP
+#ifdef HAVE_LIBPCAP
 FaceUri::FaceUri(const ethernet::Address& address)
   : m_isV6(false)
 {
   m_scheme = "ether";
   m_host = address.toString();
 }
-#endif // HAVE_PCAP
+#endif // HAVE_LIBPCAP
 
 FaceUri
 FaceUri::fromDev(const std::string& ifname)
diff --git a/daemon/core/face-uri.hpp b/daemon/core/face-uri.hpp
index 766f353..487f8f8 100644
--- a/daemon/core/face-uri.hpp
+++ b/daemon/core/face-uri.hpp
@@ -29,11 +29,11 @@
 
 namespace nfd {
 
-#ifdef HAVE_PCAP
+#ifdef HAVE_LIBPCAP
 namespace ethernet {
 class Address;
 } // namespace ethernet
-#endif // HAVE_PCAP
+#endif // HAVE_LIBPCAP
 
 /** \brief represents the underlying protocol and address used by a Face
  *  \sa http://redmine.named-data.net/projects/nfd/wiki/FaceMgmt#FaceUri
@@ -89,11 +89,11 @@
   static FaceUri
   fromFd(int fd);
 
-#ifdef HAVE_PCAP
+#ifdef HAVE_LIBPCAP
   /// construct ether canonical FaceUri
   explicit
   FaceUri(const ethernet::Address& address);
-#endif // HAVE_PCAP
+#endif // HAVE_LIBPCAP
 
   /// create dev FaceUri from network device name
   static FaceUri