Boaz Harrosh commented on the "[PATCH v5] sg: relax 16
byte cdb restriction" thread that SCSI variable length
commands (which are all SCSI commands greater than 16
bytes long) must themselves be a multiple of 4 bytes
long.

ChangeLog
   - limit the maximum cdb size permitted by the sg
     v3 interface to 252 bytes. Commands that large
     are called "variable length" and their length
     needs to be a multiple of 4.

Original patch:
   Reviewed-by: Boaz Harrosh <boaz@electrozaur.com>

Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>