Input: ims-pcu - sanity check against missing interfaces

A malicious device missing interface can make the driver oops.
Add sanity checking.

Signed-off-by: Oliver Neukum <ONeukum@suse.com>
CC: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
static int __ims_pcu_execute_command(struct ims_pcu *pcu,
				     u8 command, const void *data, size_t len,
				     u8 expected_response, int response_time)
{
	int error;

	pcu->expected_response = expected_response;
	init_completion(&pcu->cmd_done);

	error = ims_pcu_send_command(pcu, command, data, len);
	if (error)
		return error;

	if (expected_response &&
	    !wait_for_completion_timeout(&pcu->cmd_done,
					 msecs_to_jiffies(response_time))) {
		dev_dbg(pcu->dev, "Command 0x%02x timed out\n", command);
		return -ETIMEDOUT;
	}

	return 0;
}

static int __ims_pcu_execute_command(struct ims_pcu *pcu,
				     u8 command, const void *data, size_t len,
				     u8 expected_response, int response_time)
{
	int error;

	pcu->expected_response = expected_response;
	init_completion(&pcu->cmd_done);

	error = ims_pcu_send_command(pcu, command, data, len);
	if (error)
		return error;

	if (expected_response &&
	    !wait_for_completion_timeout(&pcu->cmd_done,
					 msecs_to_jiffies(response_time))) {
		dev_dbg(pcu->dev, "Command 0x%02x timed out\n", command);
		return -ETIMEDOUT;
	}

	return 0;
}
