Drop forgotten debugging statement (refs: #5571).

features/step_definitions/common_steps.rb

@@ -967,7 +967,6 @@ def share_host_files(files)
   disk_size = files.map { |f| File.new(f).size } .inject(0, :+)
   # Let's add some extra space for filesysten overhead etc.
   disk_size += [convert_to_bytes(1, 'MiB'), (disk_size * 0.10).ceil].max
-  STDERR.puts "XXX #{disk_size}"
   disk = random_alpha_string(10)
   step "I temporarily create an #{disk_size} bytes disk named \"#{disk}\""
   step "I create a gpt partition labeled \"#{disk}\" with an ext4 " +