switch fchmod(2) to fget_light()

SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group)

{

	struct file *file;

	int error = -EBADF;

	struct dentry * dentry;

	int error = -EBADF, fput_needed;

	file = fget(fd);

	file = fget_light(fd, &fput_needed);

	if (!file)

		goto out;

	error = mnt_want_write_file(file);

	if (error)

		goto out_fput;

	dentry = file->f_path.dentry;

	audit_inode(NULL, dentry);

	audit_inode(NULL, file->f_path.dentry);

	error = chown_common(&file->f_path, user, group);

	mnt_drop_write_file(file);

out_fput:

	fput(file);

	fput_light(file, fput_needed);

out:

	return error;

}