nanocoap_sock: clean up the request function
nanocoap_sock: clean up the request function

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