can: ucan: remove unused ucan_priv::intf

Field intf of struct ucan_priv is set but never used. Remove it.

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20221208081142.16936-2-mailhol.vincent@wanadoo.fr


Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>