[SCSI] scsi_pm: resume device if suspend failed

For scsi devices which use scsi bus runtime callback, runtime suspend
will call scsi_dev_type_suspend, and if the drv->suspend failed, the
device will still be in active state. But since scsi_device_quiesce is
called, the device will not be able to respond any more commands.
So add a check here to see if err occured, if so, bring the device back
to normal state with scsi_device_resume.

Signed-off-by: Aaron Lu <aaron.lu@amd.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

drivers/scsi/scsi_pm.c

@@ -24,8 +24,11 @@ static int scsi_dev_type_suspend(struct device *dev, pm_message_t msg)
 	err = scsi_device_quiesce(to_scsi_device(dev));
 	if (err == 0) {
 		drv = dev->driver;
-		if (drv && drv->suspend)
+		if (drv && drv->suspend) {
 			err = drv->suspend(dev, msg);
+			if (err)
+				scsi_device_resume(to_scsi_device(dev));
+		}
 	}
 	dev_dbg(dev, "scsi suspend: %d\n", err);
 	return err;