l2_packet_haiku: Do not specify MSG_TRUNC flag.

It doesn't have any meaning for recvfrom() in POSIX, but it
does as a Linux extension. Haiku has never implemented it,
and now returns errors when it is specified. The implementation
of this same function in l2_packet_linux does not specify MSG_TRUNC,
at least at present, so it's not needed.

Will fix https://dev.haiku-os.org/ticket/18685

src/l2_packet/l2_packet_haiku.c

@@ -127,7 +127,7 @@ static void l2_packet_receive(int sock, void *eloop_ctx, void *sock_ctx)
 	ssize_t bytesReceived;
 	u8 buffer[2300];
 
-	bytesReceived = recvfrom(l2->rx_fd, buffer, sizeof(buffer), MSG_TRUNC,
+	bytesReceived = recvfrom(l2->rx_fd, buffer, sizeof(buffer), 0,
 				 (struct sockaddr*)&from, &fromLength);
 
 	if (bytesReceived <= 0)