Merge branch 'tools-ynl-fix-errors-reported-by-ruff'

Matthieu Baerts says:

====================
tools: ynl: fix errors reported by Ruff

When looking at the YNL code to add a new feature, my text editor
automatically executed 'ruff check', and found out at least one
interesting error: one variable was used while not being defined.

I then decided to fix this error, and all the other ones reported by
Ruff. After this series, 'ruff check' reports no more errors with
version 0.12.12.
====================

Link: https://patch.msgid.link/20250909-net-next-ynl-ruff-v1-0-238c2bccdd99@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>