scsi: scsi_transport_iscsi: Use flush_work in iscsi_remove_session

scsi_flush_work flushes workqueue for the Scsi_Host.  In iSCSI offload
enabled host, this would wait for all other sessions under the host.

Use flush_work for the session being removed instead.
Signed-off-by: NJitendra Bhivare <jitendra.bhivare@broadcom.com>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Reviewed-by: NChris Leech <cleech@redhat.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/scsi_transport_iscsi.c

@@ -2158,7 +2158,6 @@ static int iscsi_iter_destroy_conn_fn(struct device *dev, void *data)
 
 void iscsi_remove_session(struct iscsi_cls_session *session)
 {
-	struct Scsi_Host *shost = iscsi_session_to_shost(session);
 	unsigned long flags;
 	int err;
 
@@ -2185,7 +2184,7 @@ void iscsi_remove_session(struct iscsi_cls_session *session)
 
 	scsi_target_unblock(&session->dev, SDEV_TRANSPORT_OFFLINE);
 	/* flush running scans then delete devices */
-	scsi_flush_work(shost);
+	flush_work(&session->scan_work);
 	__iscsi_unbind_session(&session->unbind_work);
 
 	/* hw iscsi may not have removed all connections from session */