あ、よく考えたらhalt、shutdownならpoweroffの方だった
$ uptime
09:27:13 up 21 days, 18:57, 1 user, load average: 0.46, 4.21, 5.83
# cp -v /boot/vmlinuz-generic /boot/efi/EFI/Slackware/vmlinuz.efi
'/boot/vmlinuz-generic' -> '/boot/efi/EFI/Slackware/vmlinuz.efi'
# cp -v /boot/initrd.gz /boot/efi/EFI/Slackware/initrd.gz
'/boot/initrd.gz' -> '/boot/efi/EFI/Slackware/initrd.gz'
$ uptime
09:06:27 up 29 days, 11:27, 1 user, load average: 0.10, 0.38, 0.24
Your kernel image was updated, and your /etc/lilo.conf indicates
the use of an initrd for at least one of your kernels. Be sure to
regenerate the initrd for the new kernel and handle any needed
updates to your bootloader.
はい
Upgrading kernel-modules-5.15.63-x86_64-1 package using ./kernel-modules-5.15.80-x86_64-1.txz
Upgrading kernel-generic-5.15.63-x86_64-1 package using ./kernel-generic-5.15.80-x86_64-1.txz