drm: don't unnecessarily enable the polling work

... by properly checking connector->polled. This doesn't matter too
much because the polling work itself gets this slightly more right and
doesn't set repoll if there's nothing to do. But we can do better.

v2: Chris Wilson noticed that I broke polling, since repoll will never
ever be set true. Fix this up, and simplify the logic a bit while at
it.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/drm_crtc_helper.c

@@ -974,7 +974,6 @@ static void output_poll_execute(struct work_struct *work)
 		if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD)
 			continue;
 
-		else if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT | DRM_CONNECTOR_POLL_DISCONNECT))
 		repoll = true;
 
 		old_status = connector->status;
@@ -1019,7 +1018,8 @@ void drm_kms_helper_poll_enable(struct drm_device *dev)
 		return;
 
 	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
-		if (connector->polled)
+		if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
+					 DRM_CONNECTOR_POLL_DISCONNECT))
 			poll = true;
 	}