can: etas_es58x: use devm_kzalloc() to allocate device resources

Replace kzalloc() with devm_kzalloc(). By doing this, we do not need
to care anymore about having to call kfree(). This result in a
simpler and more easy to read code.

Link: https://lore.kernel.org/r/20210628155420.1176217-4-mailhol.vincent@wanadoo.fr


Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>