iSCSI: CmdRN mandatory

[Pierre Labat <pierre_labat@hp.com>]

Julian,


Where:
======

1.2.2.1 Command numbering
"Command numbering for sessions that will only be made up
of one connection is optional."

Problem
======

The targets have to be built to  handle
the case where a session doesn't use the command numbering
and the case where a session use it.

It is :
- two code paths to test
- a code bloat
- add complexity hence potential errors


Solution
======
Make CmdRN mandatory even with one connection per session.


Regards,

Pierre