It is overkill to crash the kernel if the given message is oversize.

Drop the BUG_ON() and return -EINVAL instead.
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
Link: https://lore.kernel.org/r/20220513044143.1045728-4-tzungbi@kernel.org