Permissions for mysql 'SHOW CREATE PROCEDURE'?
the second line in man says:

To use either statement, you must be the user named in the routine DEFINER clause or have SELECT access to the mysql.proc table. If you do not have privileges for the routine itself, the value displayed for the Create Procedure or Create Function field will be NULL. 

The other option (just a suggestion) you may design a procedure or function (preferable)  to show the info in question.

Regards,