scsi: core: Avoid that a kernel warning appears during system resume

Since scsi_device_quiesce() skips SCSI devices that have another state than
RUNNING, OFFLINE or TRANSPORT_OFFLINE, scsi_device_resume() should not
complain about SCSI devices that have been skipped. Hence this patch.  This
patch avoids that the following warning appears during resume:

WARNING: CPU: 3 PID: 1039 at blk_clear_pm_only+0x2a/0x30
CPU: 3 PID: 1039 Comm: kworker/u8:49 Not tainted 5.0.0+ #1
Hardware name: LENOVO 4180F42/4180F42, BIOS 83ET75WW (1.45 ) 05/10/2013
Workqueue: events_unbound async_run_entry_fn
RIP: 0010:blk_clear_pm_only+0x2a/0x30
Call Trace:
 ? scsi_device_resume+0x28/0x50
 ? scsi_dev_type_resume+0x2b/0x80
 ? async_run_entry_fn+0x2c/0xd0
 ? process_one_work+0x1f0/0x3f0
 ? worker_thread+0x28/0x3c0
 ? process_one_work+0x3f0/0x3f0
 ? kthread+0x10c/0x130
 ? __kthread_create_on_node+0x150/0x150
 ? ret_from_fork+0x1f/0x30

Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Oleksandr Natalenko <oleksandr@natalenko.name>
Cc: Martin Steigerwald <martin@lichtvoll.de>
Cc: <stable@vger.kernel.org>
Reported-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Tested-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Fixes: 3a0a5299 ("block, scsi: Make SCSI quiesce and resume work reliably") # v4.15
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/scsi_lib.c

@@ -2548,8 +2548,10 @@ void scsi_device_resume(struct scsi_device *sdev)
 	 * device deleted during suspend)
 	 */
 	mutex_lock(&sdev->state_mutex);
-	sdev->quiesced_by = NULL;
-	blk_clear_pm_only(sdev->request_queue);
+	if (sdev->quiesced_by) {
+		sdev->quiesced_by = NULL;
+		blk_clear_pm_only(sdev->request_queue);
+	}
 	if (sdev->sdev_state == SDEV_QUIESCE)
 		scsi_device_set_state(sdev, SDEV_RUNNING);
 	mutex_unlock(&sdev->state_mutex);