tparm %l should push strlen(pop) onto the stack not insert it into the

tparm %l should push strlen(pop) onto the stack not insert it into the
result, from ncurses 5.9 patch 20130126:

    + change %l behavior in tparm to push the string length onto the
      stack rather than saving the formatted length into the output
      buffer (report by Roy Marples, cf: 980620).

ok millert