NFSv4: Turn off open-by-filehandle and NFS re-export for NFSv4.0

NFSv4: Turn off open-by-filehandle and NFS re-export for NFSv4.0

BugLink: https://bugs.launchpad.net/bugs/1995415
[ Upstream commit 2a9d683b48c8a87e61a4215792d44c90bcbbb536 ]

The NFSv4.0 protocol only supports open() by name. It cannot therefore
be used with open_by_handle() and friends, nor can it be re-exported by
knfsd.

Reported-by: Chuck Lever III <chuck.lever@oracle.com>
Fixes: 20fa19027286 ("nfs: add export operations")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>