libsmi error comment-terminates

Error text: note, -- terminates a comment

Reference: RFC 2578 section 3.4

   ASN.1 comments commence with a pair of adjacent hyphens and end with
   the next pair of adjacent hyphens or at the end of the line,
   whichever occurs first.  Comments ended by a pair of hyphens have the
   effect of a single space character.