fix autofs/afs/etc. magic mountpoint breakage

We end up trying to kfree() nd.last.name on open("/mnt/tmp", O_CREAT)
if /mnt/tmp is an autofs direct mount.  The reason is that nd.last_type
is bogus here; we want LAST_BIND for everything of that kind and we
get LAST_NORM left over from finding parent directory.

So make sure that it *is* set properly; set to LAST_BIND before
doing ->follow_link() - for normal symlinks it will be changed
by __vfs_follow_link() and everything else needs it set that way.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
static int proc_setattr(struct dentry *dentry, struct iattr *attr)
{
	int error;
	struct inode *inode = dentry->d_inode;

	if (attr->ia_valid & ATTR_MODE)
		return -EPERM;

	error = inode_change_ok(inode, attr);
	if (!error)
		error = inode_setattr(inode, attr);
	return error;
}

static int proc_setattr(struct dentry *dentry, struct iattr *attr)
{
	int error;
	struct inode *inode = dentry->d_inode;

	if (attr->ia_valid & ATTR_MODE)
		return -EPERM;

	error = inode_change_ok(inode, attr);
	if (!error)
		error = inode_setattr(inode, attr);
	return error;
}
