automake: Clean up cxxtest.cc.
'distcheck' complains on some configurations:
ERROR: files left in build directory after distclean:
./include/openvswitch/cxxtest.cc
CC: Ben Pfaff
Fixes: ("Automatically verify that OVS header files work OK in C++ also.")
@@ -64,6 +64,7 @@ include/openvswitch/cxxtest.cc: \
for header in $(openvswitchinclude_HEADERS); do \
echo $$header; \
done | sed 's,^include/\(.*\)$$,#include <\1>,'; } > $@
+CLEANFILES += include/openvswitch/cxxtest.cc
endif
# OVS does not use C++ itself, but it provides public header files
