drm/exynos: fix unnecessary resource cleanup

This patch removes unnecessary drm_mode_config_cleanup call.

Signed-off-by: Inki Dae <[e-mail]>
Signed-off-by: Kyungmin Park <[e-mail]>

drivers/gpu/drm/exynos/exynos_drm_drv.c

···
 	ret = drm_create_iommu_mapping(dev);
 	if (ret < 0) {
 		DRM_ERROR("failed to create iommu mapping.\n");
-		goto err_crtc;
+		goto err_free_private;
 	}
 
 	drm_mode_config_init(dev);
···
 err_mode_config_cleanup:
 	drm_mode_config_cleanup(dev);
 	drm_release_iommu_mapping(dev);
-err_crtc:
-	drm_mode_config_cleanup(dev);
+err_free_private:
 	kfree(private);
 
 	return ret;