You can, of course, get into big trouble for lying on a CV, but no one is advising that you do that! What you put on your CV is up to you, and in the pursuit of brevity, we are advised to include only the information that is relevant to the application. IMHO, the fact that you once withdrew from a course has little relevance to your application. I would devote the precious space on your CV to the important things, like the degree course that you did complete.