vmsplice_to_user(): switch to import_iovec()

	struct iovec iovstack[UIO_FASTIOV];

	struct iovec *iov = iovstack;

	struct iov_iter iter;

	ssize_t count;

	pipe = get_pipe_info(file);

	if (!pipe)

		return -EBADF;

	ret = rw_copy_check_uvector(READ, uiov, nr_segs,

				    ARRAY_SIZE(iovstack), iovstack, &iov);

	if (ret <= 0)

		goto out;

	count = ret;

	iov_iter_init(&iter, READ, iov, nr_segs, count);

	ret = import_iovec(READ, uiov, nr_segs,

			   ARRAY_SIZE(iovstack), &iov, &iter);

	if (ret < 0)

		return ret;

	sd.total_len = iov_iter_count(&iter);

	sd.len = 0;

	sd.total_len = count;

	sd.flags = flags;

	sd.u.data = &iter;

	sd.pos = 0;

	if (sd.total_len) {

		pipe_lock(pipe);

		ret = __splice_from_pipe(pipe, &sd, pipe_to_user);

		pipe_unlock(pipe);

	}

out:

	if (iov != iovstack)

	kfree(iov);

	return ret;

}