pkg/openwsn/sock: fix doxygen group doc
pkg/openwsn/sock: fix doxygen group doc

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