staging: vc04_services: use snprintf instead of sprintf

staging: vc04_services: use snprintf instead of sprintf

All the occurrences of sprintf usage under vc04_services can be safely
replaced by snprintf, so as to avoid any possible overflow.

Suggested-by: Dan Carpenter <dan.carpenter@linaro.org>
Suggested-by: Umang Jain <umang.jain@ideasonboard.com>
Signed-off-by: "Ricardo B. Marliere" <ricardo@marliere.net>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
Link: https://lore.kernel.org/r/20231025122632.307385-4-ricardo@marliere.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>