exfat: push rcu_barrier() from deactivate_locked_super() to filesystems

* This was introduce in:
  torvalds/linux@8c0a853

Signed-off-by: Adek Maulana <adekzmaulana@gmail.com>
Signed-off-by: Park Ju Hyung <qkrwngud825@gmail.com>

super.c

@@ -3697,6 +3697,11 @@ static int __init exfat_init_inodecache(void)
 
 static void exfat_destroy_inodecache(void)
 {
+	/*
+	 * Make sure all delayed rcu free inodes are flushed before we
+	 * destroy cache.
+	 */
+	rcu_barrier();
 	kmem_cache_destroy(exfat_inode_cachep);
 }