drm/tegra: Output cleanup functions cannot fail

The tegra_output_exit() and tegra_output_remove() functions cannot fail,
so make them return void.

Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/drivers/gpu/drm/tegra/sor.c b/drivers/gpu/drm/tegra/sor.c
index ee18adf..9e67838 100644
--- a/drivers/gpu/drm/tegra/sor.c
+++ b/drivers/gpu/drm/tegra/sor.c
@@ -1396,6 +1396,8 @@
 	struct tegra_sor *sor = host1x_client_to_sor(client);
 	int err;
 
+	tegra_output_exit(&sor->output);
+
 	if (sor->dpaux) {
 		err = tegra_dpaux_detach(sor->dpaux);
 		if (err < 0) {
@@ -1500,11 +1502,7 @@
 		return err;
 	}
 
-	err = tegra_output_remove(&sor->output);
-	if (err < 0) {
-		dev_err(&pdev->dev, "failed to remove output: %d\n", err);
-		return err;
-	}
+	tegra_output_remove(&sor->output);
 
 	return 0;
 }