[bootlin/training-materials] 9f2c28: Embedded Linux: mention the /usr merge

[Michael Opdenacker]

  Branch: refs/heads/master
  Home:   https://github.com/bootlin/training-materials
  Commit: 9f2c28d97c899972c920ca4d7500c1738979569c
      https://github.com/bootlin/training-materials/commit/9f2c28d97c899972c920ca4d7500c1738979569c
  Author: Michael Opdenacker <michael.opdenacker at bootlin.com>
  Date:   2022-04-08 (Fri, 08 Apr 2022)

  Changed paths:
    M slides/sysdev-root-filesystem-contents/sysdev-root-filesystem-contents.tex

  Log Message:
  -----------
  Embedded Linux: mention the /usr merge

Signed-off-by: Michael Opdenacker <michael.opdenacker at bootlin.com>