scsi_add_single_device — Respond to user request to probe for/add device
| int scsi_add_single_device ( | uint host, | 
| uint channel, | |
| uint id, | |
| uint lun ); | 
hostuser-supplied decimal integer
channeluser-supplied decimal integer
iduser-supplied decimal integer
lunuser-supplied decimal integer
called by writing “scsi add-single-device” to /proc/scsi/scsi.
   does scsi_host_lookup and either user_scan if that transport
   type supports it, or else scsi_scan_host_selected