ipvs: switch to sock_recvmsg()

ip_vs_receive(struct socket *sock, char *buffer, const size_t buflen)

{

	struct msghdr		msg = {NULL,};

	struct kvec		iov;

	struct kvec		iov = {buffer, buflen};

	int			len;

	EnterFunction(7);

	/* Receive a packet */

	iov.iov_base     = buffer;

	iov.iov_len      = (size_t)buflen;

	len = kernel_recvmsg(sock, &msg, &iov, 1, buflen, MSG_DONTWAIT);

	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &iov, 1, buflen);

	len = sock_recvmsg(sock, &msg, MSG_DONTWAIT);

	if (len < 0)

		return len;