commit 7c426313 upstream.

The priv->cmd_msg_buffer is allocated in the probe function, but never
kfree()ed. This patch converts the kzalloc() to resource-managed
kzalloc.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>