hdt: enhance user experience (CLI)

hdt: enhance user experience (CLI)

Some users have reported that reading the CLI can be difficult,
especially when spitting out a lot of information.

This patch:

  * adds a missing reset_more_printf() in the disk CLI
  * reduces the total scrolling to 20 lines (seems better in my testing)
  * removes a reset_more_printf() in the show disk function. This can potentially
    be bad when doing a lot of show disk 0xXX (especially after 4 in a row)
    but enhances the display when running show disks with lots of disks.

Signed-off-by: Pierre-Alexandre Meyer <pierre@mouraf.org>