Comment # 3 on bug 1164310 from Guillaume GARDET

(In reply to Fabian Vogt from comment #2)
> Why is there a /boot partition? That breaks snapshotting.
> 
> It doesn't make sense to have /boot on ext4 and /boot/grub2/arm64-efi as
> btrfs subvolume.

I think /boot was not a btrfs volume because u-boot had no support for btrfs,
so far.
Matthias enabled it very recently, so we should be able to merge /boot
partition into the btrfs volume.