Function esp_log_va 

pub unsafe extern "C" fn esp_log_va(
    config: esp_log_config_t,
    tag: *const c_char,
    format: *const c_char,
    args: va_list,
)

@brief Logs a formatted message using the provided log message configs and a variable argument list.

@param config Configuration and level of the log message. @param tag The tag string used to indicate the component from which to log. It is also used to check whether logging is enabled for that tag (depends on CONFIG_LOG_TAG_LEVEL_IMPL). If NULL then the tag is not printed. @param format The format string for the log message. @param args List of arguments.