ensure the behaviour same before:
commit b76c4672d64d226e6ea5c44fa7d3b95e2df8482c (origin/root)
Author: Xiang Xiao <xiaoxiang@xiaomi.com>
Date: Tue Sep 15 17:42:42 2020 +0800
vfs: Create a node as the root of pseudo file system
to remove the special process for root
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>