Update CLEANFILES list

Change-Id: Ia53dfeb603fc5a68e5f07c4eaa105f4154dffc45
Reviewed-on: http://review.couchbase.org/28318
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>