nfs: fix open result_flags

The protocol values here are all wrong, and miss new flags from rfc
5661.

Ping-Bug: 10649
Change-Id: I03fb2b521b415dbca5d4b77eda609eb8084da57c
Reviewed-on: https://code.wireshark.org/review/5140
Reviewed-by: Michael Mann <mmann78@netscape.net>