can: af_can: rename find_rcv_list() to can_rcv_list_find()

This patch add the commonly used prefix "can_" to the find_rcv_list()
function and add the "find" to the end, as the function returns a struct
rcv_list. This improves the overall readability of the code.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>