workqueue: deprecate system_nrt[_freezable]_wq

system_nrt[_freezable]_wq are now spurious.  Mark them deprecated and
convert all users to system[_freezable]_wq.

If you're cc'd and wondering what's going on: Now all workqueues are
non-reentrant, so there's no reason to use system_nrt[_freezable]_wq.
Please use system[_freezable]_wq instead.

This patch doesn't make any functional difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-By: Lai Jiangshan <laijs@cn.fujitsu.com>

Cc: Jens Axboe <axboe@kernel.dk>
Cc: David Airlie <airlied@linux.ie>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: David Howells <dhowells@redhat.com>
diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c
index 3252e70..8fa9d52 100644
--- a/drivers/gpu/drm/drm_crtc_helper.c
+++ b/drivers/gpu/drm/drm_crtc_helper.c
@@ -968,7 +968,7 @@
 	}
 
 	if (repoll)
-		queue_delayed_work(system_nrt_wq, delayed_work, DRM_OUTPUT_POLL_PERIOD);
+		schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD);
 }
 
 void drm_kms_helper_poll_disable(struct drm_device *dev)
@@ -993,7 +993,7 @@
 	}
 
 	if (poll)
-		queue_delayed_work(system_nrt_wq, &dev->mode_config.output_poll_work, DRM_OUTPUT_POLL_PERIOD);
+		schedule_delayed_work(&dev->mode_config.output_poll_work, DRM_OUTPUT_POLL_PERIOD);
 }
 EXPORT_SYMBOL(drm_kms_helper_poll_enable);
 
@@ -1020,6 +1020,6 @@
 	/* kill timer and schedule immediate execution, this doesn't block */
 	cancel_delayed_work(&dev->mode_config.output_poll_work);
 	if (drm_kms_helper_poll)
-		queue_delayed_work(system_nrt_wq, &dev->mode_config.output_poll_work, 0);
+		schedule_delayed_work(&dev->mode_config.output_poll_work, 0);
 }
 EXPORT_SYMBOL(drm_helper_hpd_irq_event);