[ccan] Makefile-ccan missing for create-ccan-tree?

[Eric Wong]

Hello, using "-b make" or "-b make+config" seems broken since
commit 2ee3b7c5586c283412ace072eed9d70a86368efd
("Makefile: First try at rewriting the ccan Makefile.")

	$ tools/create-ccan-tree -b make timeout timer
	<snip>
	cp: cannot stat 'tools/..//Makefile-ccan': No such file or directory
	Done. ccan source tree built in timeout
	# timeout/Makefile still has "include Makefile-ccan" in there

I'll probably find a different way to deal with Ruby extension
building, anyways, but figured I'd report it.  Thanks.