Silence Coverity CHECKED_RETURN warnings

Silence Coverity CHECKED_RETURN warnings

	CID 1458403 (#1 of 1): Unchecked return value (CHECKED_RETURN)
	8. check_return: Calling isc_socket_recv without checking
	return value (as is done elsewhere 14 out of 17 times).

121        isc_socket_recv(sock, &dev->region, 1, task, my_recv, event->ev_arg);

	CID 1458402 (#1 of 1): Unchecked return value (CHECKED_RETURN)
	2. check_return: Calling isc_socket_recv without checking
	return value (as is done elsewhere 14 out of 17 times).

149        isc_socket_recv(sock, &dev->region, 1, task, my_recv, event->ev_arg);

	CID 1458401 (#1 of 1): Unchecked return value (CHECKED_RETURN)
	6. check_return: Calling isc_socket_recv without checking
	return value (as is done elsewhere 14 out of 17 times).

226                isc_socket_recv(dev->newsocket, &region, 1,
227                                newtask, my_recv, event->ev_arg);