target: Fix target_sense_desc_format NULL pointer dereference
target: Fix target_sense_desc_format NULL pointer dereference

This patch allows target_sense_desc_format() to be called without a
valid se_device pointer, which can occur during an early exception
ahead of transport_lookup_cmd_lun() setting up se_cmd->se_device.

This addresses a v4.3-rc1 specific NULL pointer dereference
regression introduced by commit 4e4937e8.

Cc: Sagi Grimberg <380ce2a82d3d08e67ab163b51dc6d30288ad3f13@mellanox.com>
Cc: Christoph Hellwig <923f7720577207a44b32e59bbfbea59d27f1ae8e@lst.de>
Cc: Hannes Reinecke <b0d1e9e4a4e27620745ff49be9000da3174a4cc6@suse.de>
Signed-off-by: Nicholas Bellinger <978acd1567d5598152161fdf8bf3ca568f950c9b@linux-iscsi.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs