Using __user with compat_uptr_t

[David Howells <dhowells@redhat.com>]

Hi Linus,

I've added a couple of structures for dealing with 32-bit -> 64-bit upgrade of
NFS4 mounts. They represent the NFS4 mount information provided by userspace
and they contain some pointers to further userspace data. Should these further
userspace pointers be labelled __user?

For example, is this right?:

	struct compat_nfs_string {
		compat_uint_t len;
		compat_uptr_t __user data;
	};

Or is this right?:

	struct compat_nfs_string {
		compat_uint_t len;
		compat_uptr_t data;
	};

Now it makes no difference to the compiler, but it might affect the checker
tool.

David