You are calling dbms_job.submit from PL/SQL block, thus you can't use SQL*Plus bind variable.
You can either stop using jobno as SQL*Plus bind variable:
dbms_job.submit(jobno,'test.add_data;',sysdate,'sysdate+1/288');
or use SQL*Plus:
var jobno number
exec dbms_job.submit(:jobno,'test.add_data;',sysdate,'sysdate+1/288');
commit;

Do not forget the semicolon in the end of call of your procedure!

P.S. I'd recommend you to commit ...

Regards,
Ales