Fix extraclean in a different way for info+lib/sys

* Makefile.in (extraclean):
* lib/Makefile.in (extraclean): Use rmdir but suppress any
error indication.  That way, ‘make extraclean’ will remove the
directory if it’s empty, and successfully do nothing otherwise.

Makefile.in

@@ -942,6 +942,7 @@ extraclean: $(extraclean_dirs:=_extraclean)
 	-rm -f config-tmp-* aclocal.m4 configure
 	-rm -f ./*~ \#* etc/refcards/emacsver.tex doc/emacs/emacsver.texi
 	-rm -f info/*.info info/dir
+	-rmdir info 2>/dev/null
 
 # The src subdir knows how to do the right thing
 # even when the build directory and source dir are different.

lib/Makefile.in

@@ -127,6 +127,7 @@ distclean bootstrap-clean: mostlyclean
 maintainer-clean: distclean
 	rm -f TAGS gnulib.mk
 extraclean: distclean
+	-rmdir sys 2>/dev/null
 
 .PHONY: mostlyclean clean distclean bootstrap-clean maintainer-clean