7999 'format' command says "Failed to initialise libfdisk"
Reviewed by: Robert Mustacchi <rm@joyent.com>
Reviewed by: Toomas Soome <tsoome@me.com>
Reviewed by: Gary Mills <gary_mills@fastmail.fm>
Reviewed by: Garrett D'Amore <garrett@damore.org>

*** 768,792 ****
   */
  static int
  fdisk_read_master_part_table(ext_part_t *epp)
  {
          struct dk_minfo_ext dkmp_ext;
          uchar_t *buf;
          int sectsize;
          int size = sizeof (struct ipart);
          int cpcnt = FD_NUMPART * size;
  
          if (lseek(epp->dev_fd, 0, SEEK_SET) < 0) {
                  return (EIO);
          }
          if (ioctl(epp->dev_fd, DKIOCGMEDIAINFOEXT, &dkmp_ext) < 0) {
                  return (EIO);
          }
!         if (dkmp_ext.dki_lbsize < 512) {
                  return (EIO);
          }
-         sectsize = dkmp_ext.dki_lbsize;
          buf = calloc(sectsize, sizeof (uchar_t));
          if (buf == NULL) {
                  return (ENOMEM);
          }
          if (read(epp->dev_fd, buf, sectsize) < sectsize) {
--- 768,797 ----
   */
  static int
  fdisk_read_master_part_table(ext_part_t *epp)
  {
          struct dk_minfo_ext dkmp_ext;
+         struct dk_minfo dkmp;
          uchar_t *buf;
          int sectsize;
          int size = sizeof (struct ipart);
          int cpcnt = FD_NUMPART * size;
  
          if (lseek(epp->dev_fd, 0, SEEK_SET) < 0) {
                  return (EIO);
          }
          if (ioctl(epp->dev_fd, DKIOCGMEDIAINFOEXT, &dkmp_ext) < 0) {
+                 if (ioctl(epp->dev_fd, DKIOCGMEDIAINFO, &dkmp) < 0) {
                          return (EIO);
                  }
!                 sectsize = dkmp.dki_lbsize;
!         } else {
!                 sectsize = dkmp_ext.dki_lbsize;
!         }
!         if (sectsize < 512) {
                  return (EIO);
          }
          buf = calloc(sectsize, sizeof (uchar_t));
          if (buf == NULL) {
                  return (ENOMEM);
          }
          if (read(epp->dev_fd, buf, sectsize) < sectsize) {