drm/armada: allow armada_drm_plane_work_queue() to silently fail

Avoid printing an error message when armada_drm_plane_work_queue() is
unable to get the vblank (eg, because we're doing a modeset.)  Continue
to report the failure to the caller, so the caller can handle this.

Move the error message into armada_ovl_plane_update().
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

drivers/gpu/drm/armada/armada_crtc.c

@@ -254,10 +254,8 @@ int armada_drm_plane_work_queue(struct armada_crtc *dcrtc,
 	int ret;
 
 	ret = drm_crtc_vblank_get(&dcrtc->crtc);
-	if (ret) {
-		DRM_ERROR("failed to acquire vblank counter\n");
+	if (ret)
 		return ret;
-	}
 
 	ret = cmpxchg(&plane->work, NULL, work) ? -EBUSY : 0;
 	if (ret)

drivers/gpu/drm/armada/armada_overlay.c

@@ -245,7 +245,9 @@ armada_ovl_plane_update(struct drm_plane *plane, struct drm_crtc *crtc,
 	if (idx) {
 		armada_reg_queue_end(work->regs, idx);
 		/* Queue it for update on the next interrupt if we are enabled */
-		armada_drm_plane_work_queue(dcrtc, work);
+		ret = armada_drm_plane_work_queue(dcrtc, work);
+		if (ret)
+			DRM_ERROR("failed to queue plane work: %d\n", ret);
 	}
 	return 0;
 }