drm/exynos: propagate plane initialization errors

In case of error during plane initialization load callback
incorrectly return success, this patch fixes it.
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

drivers/gpu/drm/exynos/exynos_drm_drv.c

@@ -87,7 +87,10 @@ static int exynos_drm_load(struct drm_device *dev, unsigned long flags)
 
 		plane = exynos_plane_init(dev, possible_crtcs,
 					  DRM_PLANE_TYPE_OVERLAY);
-		if (IS_ERR(plane))
+		if (!IS_ERR(plane))
+			continue;
+
+		ret = PTR_ERR(plane);
 		goto err_mode_config_cleanup;
 	}