[bootlin/training-materials] 7c3400: yocto-image: update update syntax

[Alexandre Belloni]

  Branch: refs/heads/master
  Home:   https://github.com/bootlin/training-materials
  Commit: 7c340041df444b6b63515671aad873cc898446c7
      https://github.com/bootlin/training-materials/commit/7c340041df444b6b63515671aad873cc898446c7
  Author: Alexandre Belloni <alexandre.belloni at bootlin.com>
  Date:   2022-10-27 (Thu, 27 Oct 2022)

  Changed paths:
    M slides/yocto-image/yocto-image.tex

  Log Message:
  -----------
  yocto-image: update update syntax

Signed-off-by: Alexandre Belloni <alexandre.belloni at bootlin.com>