Fix 'camcontrol inquiry'. The inquiry data structure changes (increased to

Fix 'camcontrol inquiry'.  The inquiry data structure changes (increased to
256 bytes) caused it to break on many devices.

The SCSI spec says that for commands with 8-bit length fields, a value of 0
means 256 bytes.  As it turns out, many devices don't deal with that
properly.  Some interpret the 0 as 0, and return no data.  Others return
more than 256 bytes of data, and cause an overrun.

The fix is to tell the device we've only allocated SHORT_INQUIRY_LENGTH (36
bytes) of inquiry data, instead of sizeof(struct scsi_inquiry_data).

camcontrol.c:		Change inq_len in the call to scsi_inquiry() to
			SHORT_INQUIRY_LENGTH, and add a long comment
			explaining the reason for the change.

scsi_all.h:		Add a comment above the definitinon of
			SHORT_INQUIRY_LENGTH alerting people that it is
			both the initial probe inquiry length, and the
			minimum amount of data needed for scsi_print_inquiry()
			to function.

scsi_all.c:		Add a comment about SHORT_INQUIRY_LENGTH being the
			minimum amount of data needed for
			scsi_print_inquiry() to function.

Reviewed by:	gibbs
Approved by:	jkh
Reported by:	"John W. DeBoskey" <jwd@unx.sas.com>