drm/exynos: fixed bug to exynos_drm_fb_dev_reinit().

this patch solves the problem that fb_helper is released
when exynos_drm_fbdev_reinit() was called. if this function call
is ok then just return.
Signed-off-by: NInki Dae <inki.dae@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

drivers/gpu/drm/exynos/exynos_drm_fbdev.c

@@ -432,6 +432,8 @@ int exynos_drm_fbdev_reinit(struct drm_device *dev)
 		return exynos_drm_fbdev_init(dev);
 	}
 
+	return ret;
+
 err:
 	/*
 	 * if drm_load() failed when drm load() was called prior