commit de3997a7 upstream.

This was an omission from 8c18f205
"nfsd41: SUPPATTR_EXCLCREAT attribute".

Cc: Benny Halevy <bhalevy@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>