can: etas_es58x: es58x_rx_err_msg(): fix memory leak in error path

In es58x_rx_err_msg(), if can->do_set_mode() fails, the function
directly returns without calling netif_rx(skb). This means that the
skb previously allocated by alloc_can_err_skb() is not freed. In other
terms, this is a memory leak.

This patch simply removes the return statement in the error branch and
let the function continue.

Issue was found with GCC -fanalyzer, please follow the link below for
details.

Fixes: 85372578 ("can: etas_es58x: add core support for ETAS ES58X CAN USB interfaces")
Link: https://lore.kernel.org/all/20211026180740.1953265-1-mailhol.vincent@wanadoo.fr


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