Input: hyperv-keyboard: Use in-place iterator API in the channel callback

static void hv_kbd_on_channel_callback(void *context)

{

	struct vmpacket_descriptor *desc;

	struct hv_device *hv_dev = context;

	void *buffer;

	int bufferlen = 0x100; /* Start with sensible size */

	u32 bytes_recvd;

	u64 req_id;

	int error;

	buffer = kmalloc(bufferlen, GFP_ATOMIC);

	if (!buffer)

		return;

	while (1) {

		error = vmbus_recvpacket_raw(hv_dev->channel, buffer, bufferlen,

					     &bytes_recvd, &req_id);

		switch (error) {

		case 0:

			if (bytes_recvd == 0) {

				kfree(buffer);

				return;

			}

			hv_kbd_handle_received_packet(hv_dev, buffer,

						      bytes_recvd, req_id);

			break;

	foreach_vmbus_pkt(desc, hv_dev->channel) {

		bytes_recvd = desc->len8 * 8;

		req_id = desc->trans_id;

		case -ENOBUFS:

			kfree(buffer);

			/* Handle large packet */

			bufferlen = bytes_recvd;

			buffer = kmalloc(bytes_recvd, GFP_ATOMIC);

			if (!buffer)

				return;

			break;

		}

		hv_kbd_handle_received_packet(hv_dev, desc, bytes_recvd,

					      req_id);

	}

}