[bootlin/training-materials] 1e9e5c: yocto-recipe-extra: fix grammar

[Alexandre Belloni]

  Branch: refs/heads/master
  Home:   https://github.com/bootlin/training-materials
  Commit: 1e9e5c6375f3242abbb61daf8200148117fd8984
      https://github.com/bootlin/training-materials/commit/1e9e5c6375f3242abbb61daf8200148117fd8984
  Author: Alexandre Belloni <alexandre.belloni at bootlin.com>
  Date:   2023-01-24 (Tue, 24 Jan 2023)

  Changed paths:
    M slides/yocto-recipe-extra/yocto-recipe-extra.tex

  Log Message:
  -----------
  yocto-recipe-extra: fix grammar

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