NFSv4: Don't send delegation-related share access modes to CLOSE

When we set the new share access modes for CLOSE in nfs4_close_prepare().
we should only set a mode of NFS4_SHARE_ACCESS_READ, NFS4_SHARE_ACCESS_WRITE
or NFS4_SHARE_ACCESS_BOTH. Currently, we may also be passing in the NFSv4.1
share modes for controlling delegation requests in OPEN, which is wrong.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>