Merge patch series "can: esd_usb: Some more preparation for supporting esd CAN-USB/3"

Frank Jungclaus <frank.jungclaus@esd.eu> says:

Another small batch of patches to be seen as preparation for adding
support of the newly available esd CAN-USB/3 to esd_usb.c.

Due to some unresolved questions adding support for
CAN_CTRLMODE_BERR_REPORTING has been postponed to one of the future
patches.

v2 -> v3:
 * More specific subjects
 * Try to use imperative instead of past tense

v1 -> v2: https://lore.kernel.org/all/20230214160223.1199464-1-frank.jungclaus@esd.eu
 * [Patch v2 1/3]: No changes.
 * [Patch v2 2/3]: Make use of can_change_state() and relocate testing
   alloc_can_err_skb() for NULL to the end of esd_usb_rx_event(), to
   have things like can_bus_off(), can_change_state() working even in
   out of memory conditions.
 * [Patch v2 3/3]: No changes. I will 'declare esd_usb_msg as an union
   instead of a struct' in a separate follow-up patch.

v1: https://lore.kernel.org/all/20221219212013.1294820-1-frank.jungclaus@esd.eu
    https://lore.kernel.org/all/20221219212717.1298282-1-frank.jungclaus@esd.eu

Link: https://lore.kernel.org/all/20230216190450.3901254-1-frank.jungclaus@esd.eu
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>