Description: nfsd4: readdirplus shouldn't return parent of export
References:
 https://patchwork.kernel.org/project/linux-nfs/patch/20210111210129.GA11652@fieldses.org/
Notes:
Bugs:
upstream: released (5.11-rc5) [51b2ee7d006a736a9126e8111d1f24e4fd0afaa6]
5.10-upstream-stable: released (5.10.10) [fdcaa4af5e70e2d984c9620a09e9dade067f2620]
4.19-upstream-stable: released (4.19.170) [a08c2e586ad047fcea3f75664cca0915c77934fe]
4.9-upstream-stable: released (4.9.253) [2174b2cf3960b9091c2516feeb9e345fe24f8906]
sid: released (5.10.12-1)
4.19-buster-security: released (4.19.171-1)
4.9-stretch-security: released (4.9.258-1)