MFC: r276347

MFC: r276347
r245508 modified the NFS client's Setattr RPC to
use VA_UTIMES_NULL to indicate whether it should
set the time to the current tod on the server.
This had the side effect of making the NFS client
use the client's timestamp for exclusive create,
starting with FreeBSD9.2.
Unfortunately a bug in some Solaris NFS servers
causes these servers to return NFS_OK to the
Setattr RPC done during exclusive create, but not
actually set the file's mode, leaving the file's
mode == 0.
This patch restores the NFS client's behaviour to
use the server's tod for the exclusive open's
Setattr RPC, to avoid the Solaris server bug and
to restore the pre-FreeBSD9.2 NFS behaviour.

git-svn-id: svn://svn.freebsd.org/base/stable/9@281385 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f