can: ucan: fix typos in comments

Various spelling mistakes in comments.
Detected with the help of Coccinelle.

Link: https://lore.kernel.org/all/20220314115354.144023-28-Julia.Lawall@inria.fr


Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>