scsi: qla2xxx: Spinlock recursion in qla_target

The patch reverts changes done in qlt_schedule_sess_for_deletion() to
avoid spinlock recursion sess->vha->work_lock should be used instead
of ha->tgt.sess_lock, that can be locked in callers: qlt_reset() or
qlt_handle_login()

[mkp: roll in build warning reported by sfr]

Fixes: 1c6cacf4ea6c04 ("scsi: qla2xxx: Fixup locking for session deletion")
Cc: <stable@vger.kernel.org> #v4.17
Signed-off-by: Mikhail Malygin <m.malygin@yadro.com>
Reported-by: Mikhail Malygin <m.malygin@yadro.com>
Tested-by: Mikhail Malygin <m.malygin@yadro.com>
Acked-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/qla2xxx/qla_target.c

@@ -1224,7 +1224,6 @@ static void qla24xx_chk_fcp_state(struct fc_port *sess)
 void qlt_schedule_sess_for_deletion(struct fc_port *sess)
 {
 	struct qla_tgt *tgt = sess->tgt;
-	struct qla_hw_data *ha = sess->vha->hw;
 	unsigned long flags;
 
 	if (sess->disc_state == DSC_DELETE_PEND)
@@ -1241,16 +1240,16 @@ void qlt_schedule_sess_for_deletion(struct fc_port *sess)
 			return;
 	}
 
-	spin_lock_irqsave(&ha->tgt.sess_lock, flags);
 	if (sess->deleted == QLA_SESS_DELETED)
 		sess->logout_on_delete = 0;
 
+	spin_lock_irqsave(&sess->vha->work_lock, flags);
 	if (sess->deleted == QLA_SESS_DELETION_IN_PROGRESS) {
-		spin_unlock_irqrestore(&ha->tgt.sess_lock, flags);
+		spin_unlock_irqrestore(&sess->vha->work_lock, flags);
 		return;
 	}
 	sess->deleted = QLA_SESS_DELETION_IN_PROGRESS;
-	spin_unlock_irqrestore(&ha->tgt.sess_lock, flags);
+	spin_unlock_irqrestore(&sess->vha->work_lock, flags);
 
 	sess->disc_state = DSC_DELETE_PEND;