NFS: NFS version number is unsigned

RPC protocol version numbers are unsigned.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

include/linux/nfs_xdr.h

@@ -774,7 +774,7 @@ struct nfs_access_entry;
  * RPC procedure vector for NFSv2/NFSv3 demuxing
  */
 struct nfs_rpc_ops {
-	int	version;		/* Protocol version */
+	u32	version;		/* Protocol version */
 	struct dentry_operations *dentry_ops;
 	const struct inode_operations *dir_inode_ops;
 	const struct inode_operations *file_inode_ops;