NFSv4: Fix an atomicity problem in CLOSE

If we are to remove the serialisation of OPEN/CLOSE, then we need to
ensure that the stateid sent as part of a CLOSE operation does not
change after we test the state in nfs4_close_prepare.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 467c84e..7e38d64 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -389,7 +389,7 @@
 struct nfs_closeargs {
 	struct nfs4_sequence_args	seq_args;
 	struct nfs_fh *         fh;
-	nfs4_stateid *		stateid;
+	nfs4_stateid 		stateid;
 	struct nfs_seqid *	seqid;
 	fmode_t			fmode;
 	const u32 *		bitmask;