You can turn on or off support for minorversions using e.g.
echo "-4.2" >/proc/fs/nfsd/versions
However, the current implementation is a little wonky. For example, the
above will turn off 4.2 support, but it will also turn *on* 4.1 support.
This didn't matter as long as we only had 2 minorversions, which was
true till very recently.
And do a little cleanup here.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>