tests/usbus: resolve vera++ issue
tests/usbus: resolve vera++ issue

kaspar030/RIOT,jasonatran/RIOT,ant9000/RIOT,miri64/RIOT,kaspar030/RIOT,jasonatran/RIOT,RIOT-OS/RIOT,ant9000/RIOT,OlegHahm/RIOT,ant9000/RIOT,OlegHahm/RIOT,kYc0o/RIOT,miri64/RIOT,kaspar030/RIOT,ant9000/RIOT,kYc0o/RIOT,miri64/RIOT,OlegHahm/RIOT,jasonatran/RIOT,miri64/RIOT,kaspar030/RIOT,OlegHahm/RIOT,RIOT-OS/RIOT,kYc0o/RIOT,OlegHahm/RIOT,kYc0o/RIOT,RIOT-OS/RIOT,kaspar030/RIOT,ant9000/RIOT,miri64/RIOT,RIOT-OS/RIOT,jasonatran/RIOT,RIOT-OS/RIOT,kYc0o/RIOT,jasonatran/RIOT