qla2xxx: Get rid of redundant qla_tgt_sess.tearing_down

The only place that sets qla_tgt_sess.tearing_down calls
target_splice_sess_cmd_list() immediately afterwards, without dropping
the lock it holds.  That function sets se_session.sess_tearing_down,
so we can get rid of the qla_target-specific flag, and in the one
place that looks at the qla_tgt_sess.tearing_down flag just test
se_session.sess_tearing_down instead.

Cc: Chad Dupuis <chad.dupuis@qlogic.com>
Cc: Arun Easi <arun.easi@qlogic.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/scsi/qla2xxx/qla_target.c

@@ -2644,7 +2644,7 @@ static void qlt_do_work(struct work_struct *work)
 	sess = ha->tgt.tgt_ops->find_sess_by_s_id(vha,
 	    atio->u.isp24.fcp_hdr.s_id);
 	if (sess) {
-		if (unlikely(sess->tearing_down)) {
+		if (unlikely(sess->se_sess->sess_tearing_down)) {
 			sess = NULL;
 			spin_unlock_irqrestore(&ha->hardware_lock, flags);
 			goto out_term;

drivers/scsi/qla2xxx/qla_target.h

@@ -813,7 +813,6 @@ struct qla_tgt_sess {
 	unsigned int conf_compl_supported:1;
 	unsigned int deleted:1;
 	unsigned int local:1;
-	unsigned int tearing_down:1;
 
 	struct se_session *se_sess;
 	struct scsi_qla_host *vha;

drivers/scsi/qla2xxx/tcm_qla2xxx.c

@@ -464,7 +464,6 @@ static int tcm_qla2xxx_shutdown_session(struct se_session *se_sess)
 	vha = sess->vha;
 
 	spin_lock_irqsave(&vha->hw->hardware_lock, flags);
-	sess->tearing_down = 1;
 	target_splice_sess_cmd_list(se_sess);
 	spin_unlock_irqrestore(&vha->hw->hardware_lock, flags);