This is not really an ODS or reporting procedure question. However, when you use the DATA step and CALL SYMPUT to make your macro variables, you are responsible for trimming the data step variables yourself.
My preferred method is to just use %SUBSTR and the %LET -- which the macro facility usually trims for you. Compare the LOG (and the %PUT output) for both of these examples. For more help with the Macro coding, contact Tech Suport.
*** 1) only use %LET and %SUBSTR;
*** use %LET statement and NOT datastep;
*** %LET will strip trailing blanks for you;