6110 dumpadm usage string should mention '-d none'

*** 33,44 ****
  #include "dconf.h"
  #include "minfree.h"
  #include "utils.h"
  
  static const char USAGE[] = "\
! Usage: %s [-enuy] [-c kernel | curproc | all ] [-d dump-device | swap ]\n\
!         [-m min {k|m|%%} ] [-s savecore-dir] [-r root-dir] [-z on|off]\n";
  
  static const char OPTS[] = "einuyc:d:m:s:r:z:";
  
  static const char PATH_DEVICE[] = "/dev/dump";
  static const char PATH_CONFIG[] = "/etc/dumpadm.conf";
--- 33,45 ----
  #include "dconf.h"
  #include "minfree.h"
  #include "utils.h"
  
  static const char USAGE[] = "\
! Usage: %s [-enuy] [-c kernel | curproc | all ]\n\
!         [-d dump-device | swap | none ] [-m min {k|m|%%} ] [-s savecore-dir]\n\
!         [-r root-dir] [-z on|off]\n";
  
  static const char OPTS[] = "einuyc:d:m:s:r:z:";
  
  static const char PATH_DEVICE[] = "/dev/dump";
  static const char PATH_CONFIG[] = "/etc/dumpadm.conf";