Cleanup the code coverage files

Makefile.global

@@ -71,6 +71,7 @@ utest: all
 	fi
 
 clean:
+	find . -name \*.gcno -o -name \*.gcda | xargs rm -f
 	find . -name \*.lo -o -name \*.o | xargs rm -f
 	find . -name \*.la -o -name \*.a | xargs rm -f 
 	find . -name \*.so | xargs rm -f