NFSv4: Fix a potential CLOSE race

Once the state_owner and lock_owner semaphores get removed, it will be
 possible for other OPEN requests to reopen the same file if they have
 lower sequence ids than our CLOSE call.
 This patch ensures that we recheck the file state once
 nfs_wait_on_sequence() has completed waiting.

 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

include/linux/nfs_xdr.h

@@ -149,7 +149,7 @@ struct nfs_open_confirmres {
  */
 struct nfs_closeargs {
 	struct nfs_fh *         fh;
-	nfs4_stateid            stateid;
+	nfs4_stateid *		stateid;
 	struct nfs_seqid *	seqid;
 	int			open_flags;
 };