Use C++ compiler when linking

Index: examples/lg/Makefile.am
--- examples/lg/Makefile.am.orig
+++ examples/lg/Makefile.am
@@ -1,3 +1,5 @@
+CCLD = $(CXX)
+
 AM_CFLAGS = $(PMACCT_CFLAGS)
 
 if USING_BGP_BINS