drm/tegra: Add missing clk_disable_unprepare() in tegra_dc_probe()

Add the missing clk_disable_unprepare() before return from
tegra_dc_probe() in the error handling path.

Fixes: f68ba691 ("drm/tegra: dc: Link DC1 to DC0 on Tegra20")
Signed-off-by: Zhang Zekun <zhangzekun11@huawei.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/gpu/drm/tegra/dc.c

@@ -3205,8 +3205,10 @@ static int tegra_dc_probe(struct platform_device *pdev)
 	usleep_range(2000, 4000);
 
 	err = reset_control_assert(dc->rst);
-	if (err < 0)
+	if (err < 0) {
+		clk_disable_unprepare(dc->clk);
 		return err;
+	}
 
 	usleep_range(2000, 4000);