drm: Use a nondestructive mode for output detect when polling (v2)

v2: Julien Cristau pointed out that @nondestructive results in
double-negatives and confusion when trying to interpret the parameter,
so use @force instead. Much easier to type as well. ;-)

And fix the miscompilation of vmgfx reported by Sedat Dilek.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c
index fb6b70f..dcbeb98 100644
--- a/drivers/gpu/drm/drm_crtc_helper.c
+++ b/drivers/gpu/drm/drm_crtc_helper.c
@@ -103,7 +103,7 @@
 		if (connector->funcs->force)
 			connector->funcs->force(connector);
 	} else {
-		connector->status = connector->funcs->detect(connector, false);
+		connector->status = connector->funcs->detect(connector, true);
 		drm_kms_helper_poll_enable(dev);
 	}
 
@@ -866,7 +866,7 @@
 		    !(connector->polled & DRM_CONNECTOR_POLL_HPD))
 			continue;
 
-		status = connector->funcs->detect(connector, true);
+		status = connector->funcs->detect(connector, false);
 		if (old_status != status)
 			changed = true;
 	}