nfs: Don't setting FILE_CREATED flags always

Commit 5bc2afc2 "NFSv4: Honour the 'opened' parameter in the atomic_open()
 filesystem method" have support the opened arguments now.

Also,
Commit 03da633a "atomic_open: take care of EEXIST in no-open case with
 O_CREAT|O_EXCL in fs/namei.c" have change vfs's logical.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>