[arch-releng] Squashfs

Currently to convert root-image to a real install we unsquash root-image.fs.sfs then mount root-image.fs then copy from there. We have already got image mounted /dev/loop0 on /run/archiso/sfs/root-image type squashfs (ro,relatime) Trying to take out an unsquash action to reduce install time, it will only work if I can mount /run/archiso/sfs/root-image/root-image.fs Have feeling I am not going to be able to mount it twice. MrG