If layout is marked by NFS_LAYOUT_RETURN_BEFORE_CLOSE, we should always
send LAYOUTRETURN before close, and we don't need to do ROC drain if we
do send LAYOUTRETURN.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>