target: Prevent transport_send_task_abort when CHECK_CONDITION status

This patch fixes a bug where transport_send_task_abort() could be called
during LUN_RESET to return SAM_STAT_TASK_ABORTED + tfo->queue_status(), when
SCF_SENT_CHECK_CONDITION -> tfo->queue_status() has already been sent from
within another context via transport_send_check_condition_and_sense().

Cc: stable@kernel.org
Signed-off-by: Nicholas Bellinger <nab@risingtidesystems.com>

drivers/target/target_core_transport.c

@@ -4919,6 +4919,15 @@ EXPORT_SYMBOL(transport_check_aborted_status);
 
 void transport_send_task_abort(struct se_cmd *cmd)
 {
+	unsigned long flags;
+
+	spin_lock_irqsave(&cmd->t_state_lock, flags);
+	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
+		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+		return;
+	}
+	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+
 	/*
 	 * If there are still expected incoming fabric WRITEs, we wait
 	 * until until they have completed before sending a TASK_ABORTED