can: bittiming: can_validate_bitrate(): simplify bit rate checking

This patch simplifies the validation of the fixed bit rates. If a
supported bit rate is found, directly return 0.

If no valid bit rate is found return -EINVAL;

Link: https://lore.kernel.org/all/20220124215642.3474154-6-mkl@pengutronix.de


Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>