target: Allow non zero ListID in EXTENDED_COPY parameter list

This patch changes target_do_xcopy() to allow processing of non-zero
ListIDs in EXTENDED_COPY parameter list data, instead of returning
CHECK_CONDITION status.

As the copy offload implementation reports SNLID=1 (Supports No ListID)
in OPERATING PARAMETERS, any ListID value presented by the client is
currently ignored.

Also, properly extract list_id_usage for informational purposes.

Reported-by: Thomas Glanzmann <thomas@glanzmann.de>
Reported-by: Douglas Gilbert <dgilbert@interlog.com>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>