target: use correct sense code for LUN communication failure

target: use correct sense code for LUN communication failure

commit 18a9df42d53fabfa43b78be1104838cc8b9762e1 upstream.

The ASC/ASCQ code for 'Logical Unit Communication failure' is
0x08/0x00; 0x80/0x00 is vendor specific.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Cc: Nicholas Bellinger <nab@risingtidesystems.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
[bwh: Backported to 3.2: add offset to buffer index]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>