nfs/flexfiles: send layoutreturn before freeing lseg
nfs/flexfiles: send layoutreturn before freeing lseg

Otherwise we'll lose error tracking information when
encoding layoutreturn.

pnfs_put_lseg may be called from rpc callbacks. So we should not
call pnfs_send_layoutreturn directly because it can deadlock in
the rpc layer.

Signed-off-by: Peng Tao <4fb2b5cc20694ed9d470f738b651303a1e636b2d@primarydata.com>
Signed-off-by: Tom Haynes <465074408fd535fb65d31a2afcd44a150dbbf651@primarydata.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs