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>
diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.c b/drivers/gpu/drm/exynos/exynos_drm_drv.c
index 510d7cb..23fbad5 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_drv.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_drv.c
@@ -87,8 +87,11 @@
 
 		plane = exynos_plane_init(dev, possible_crtcs,
 					  DRM_PLANE_TYPE_OVERLAY);
-		if (IS_ERR(plane))
-			goto err_mode_config_cleanup;
+		if (!IS_ERR(plane))
+			continue;
+
+		ret = PTR_ERR(plane);
+		goto err_mode_config_cleanup;
 	}
 
 	/* init kms poll for handling hpd */