drm/exynos: Remove unnecessary checking

It is not needed since drm_atomic_helper_shutdown checks it.

Signed-off-by: Guoqing Jiang <[e-mail]>
Signed-off-by: Inki Dae <[e-mail]>

drivers/gpu/drm/exynos/exynos_drm_drv.c

···
 {
 	struct drm_device *drm = platform_get_drvdata(pdev);
 
-	if (drm)
-		drm_atomic_helper_shutdown(drm);
+	drm_atomic_helper_shutdown(drm);
 }
 
 static struct platform_driver exynos_drm_platform_driver = {