- simplify rdtmp and $ramdisk creation and keep only in `unpack_ramdisk`
- fix `reset_ak` and `setup_ak` behavior if run before $block is set
- only save boot.img and boot-new.img in *-files subdirectories on multi-partition setups since otherwise the tmpfs (in recovery) and ext4 .img (when booted) size usage gets quickly out of hand
- fix slot_select=inactive when used with block=auto or block=boot partition detection