• clean code
• add a option to : specific path to ignore during run grub-mkconfig
  e.g :

  Found Snapshot: 2016-03-31 10:26:52 var/lib/docker/btrfs/subvolumes/74040aee4fa

docker is not a real snapshot available to boot
add : GRUB_BTRFS_IGNORE_SPECIFIC_PATH=("var/lib/docker") to your /etc/default/grub
and this path will be skip during run grub-mkconfig

Warning : copy exactly the right path (var/lib/docker , not /var/lib/docker/), do not put the full path