[bootlin/training-materials] 2468c9: Kernel labs: use make kernelversion

[Clément Léger]

  Branch: refs/heads/master
  Home:   https://github.com/bootlin/training-materials
  Commit: 2468c9f2505d72dfca3e75657baebc0182cd4024
      https://github.com/bootlin/training-materials/commit/2468c9f2505d72dfca3e75657baebc0182cd4024
  Author: Clément Léger <clement.leger at bootlin.com>
  Date:   2021-12-14 (Tue, 14 Dec 2021)

  Changed paths:
    M labs/kernel-sources-exploring/kernel-sources-exploring.tex

  Log Message:
  -----------
  Kernel labs: use make kernelversion

Use make kernelversion to check kernel version (But also mention that
this information is visible in the Makefile).

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