[bootlin/training-materials] 6c6cbe: labs: kgdb: improve explanations

[Clément Léger]

  Branch: refs/heads/master
  Home:   https://github.com/bootlin/training-materials
  Commit: 6c6cbed5396bcd45d1d65e1c7352694a81623375
      https://github.com/bootlin/training-materials/commit/6c6cbed5396bcd45d1d65e1c7352694a81623375
  Author: Clément Léger <clement.leger at bootlin.com>
  Date:   2023-03-24 (Fri, 24 Mar 2023)

  Changed paths:
    M lab-data/debugging/nfsroot/root/kgdb/kgdb_test.c
    M labs/debugging-kernel-debugging/debugging-kernel-debugging.tex

  Log Message:
  -----------
  labs: kgdb: improve explanations

Improve kgdb and add a paragraph about kptr_restrict setting.

Signed-off-by: Clément Léger <clement.leger at bootlin.com>