Before Update Trigger SQL SERVER 2012

alter TRIGGER AsignacionHorasDocente_TRG    
on tbdocentes
after UPDATE
as
BEGIN
DECLARE @nhoraCurso INT = (select sum(hor_curso) from tbcursos where id_categoria=1);
DECLARE @nhoraDocente INT = (select sum(hdi_docente) from tbDocentes where id_categoria=1);     
    IF @nhoraCurso < @nhoraDocente
    BEGIN
    PRINT '-------- NO SE PUEDE MODIFICAR PORQUE YA CUMPLIO LA DEMANDA DE HORAS PROGRAMADAS --------';      
    rollback
    END 
END

What I need is that the row can not be modified if it complies with the condition @nhoraCurso < @nhoraDocente, the problem is that I get the following message:

  

-------- CAN NOT BE MODIFIED BECAUSE I ALREADY COMPLY WITH THE DEMAND OF SCHEDULED HOURS --------

     

Msg 3609, Level 16, State 1, Line 1

     

The transaction ended in the trigger. The batch has been aborted.

is there any way to hide or delete the 3609 message or another way of doing what I need?