landlock: Fix grammar error

Fix grammar error in comments that were identified using the codespell
tool.

Signed-off-by: Tanya Agarwal <tanyaagarwal25699@gmail.com>
Reviewed-by: Günther Noack <gnoack@google.com>
Link: https://lore.kernel.org/r/20250123194208.2660-1-tanyaagarwal25699@gmail.com


[mic: Simplify commit message]
Signed-off-by: Mickaël Salaün <mic@digikod.net>