mISDN: switch to sock_recvmsg()

here we do need to reinitialize ->msg_iter on each call - the
data in buffer is overwritten every time, not appended to.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

drivers/isdn/mISDN/l1oip_core.c

@@ -645,8 +645,10 @@ l1oip_socket_thread(void *data)
 {
 	struct l1oip *hc = (struct l1oip *)data;
 	int ret = 0;
-	struct msghdr msg;
 	struct sockaddr_in sin_rx;
+	struct kvec iov;
+	struct msghdr msg = {.msg_name = &sin_rx,
+			     .msg_namelen = sizeof(sin_rx)};
 	unsigned char *recvbuf;
 	size_t recvbuf_size = 1500;
 	int recvlen;
@@ -661,6 +663,9 @@ l1oip_socket_thread(void *data)
 		goto fail;
 	}
 
+	iov.iov_base = recvbuf;
+	iov.iov_len = recvbuf_size;
+
 	/* make daemon */
 	allow_signal(SIGTERM);
 
@@ -697,12 +702,6 @@ l1oip_socket_thread(void *data)
 		goto fail;
 	}
 
-	/* build receive message */
-	msg.msg_name = &sin_rx;
-	msg.msg_namelen = sizeof(sin_rx);
-	msg.msg_control = NULL;
-	msg.msg_controllen = 0;
-
 	/* build send message */
 	hc->sendmsg.msg_name = &hc->sin_remote;
 	hc->sendmsg.msg_namelen = sizeof(hc->sin_remote);
@@ -719,12 +718,9 @@ l1oip_socket_thread(void *data)
 		printk(KERN_DEBUG "%s: socket created and open\n",
 		       __func__);
 	while (!signal_pending(current)) {
-		struct kvec iov = {
-			.iov_base = recvbuf,
-			.iov_len = recvbuf_size,
-		};
-		recvlen = kernel_recvmsg(socket, &msg, &iov, 1,
-					 recvbuf_size, 0);
+		iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &iov, 1,
+				recvbuf_size);
+		recvlen = sock_recvmsg(socket, &msg, 0);
 		if (recvlen > 0) {
 			l1oip_socket_parse(hc, &sin_rx, recvbuf, recvlen);
 		} else {