[CARE]: number of LUNS from REPORT LUNS data report and macros

[Luben Tuikov <luben@splentec.com>]

Two issues here.

Firstly, I don't think that one can quite do
``num_luns = (length / sizeof(ScsiLun));'' in scsi_scan.c.

The reason is that we should keep clear separation of what/how
the kernel represents some standard/drafts data and how it comes
from the device. I.e. one wouldn't assume (one step further) that
_also_ the byte ordering is the same in the report data and in ScsiLun,
i.e.  (ScsiLun *)(data+i*sizeof(ScsiLun)) ... not!

A SCSI LUN should be represented by ``u64''. Futhermore, only
a LLDD should poplulate such a variable (as outlined in another email)
directly or indirectly (though REPORT LUNS data).

Secondly, please get rid of the big
#ifdef CONFIG_SCSI_REPORT_LUNS in scsi_scan.c.
Linus has made this a point numerous times.

Lets keep this great subsystem great!

(Those issues should naturally go away once u64 LUN is adopted.)

-- 
Luben