Await echo at the initialization

Echo is seemingly being sent right after the synchronization. Await echo replies starting from the very begin of the communication.

lpc.c

@@ -65,12 +65,14 @@ void lpc_init(struct lpc_device *dev) {
     sprog_error("Synchronization successful\n");
   printf("Synchronized\r\n");
   fflush(stdout);
+  fgets(buf, sizeof(buf), stdin); /* deny echoed line */
   fgets(buf, sizeof(buf), stdin);
   if(strcmp(buf, "OK\r\n")!=0)
     sprog_error("Expected OK, received '%s'\n", buf);
   sprog_error("Sending clock frequency\n");
   printf("12000\r\n");
   fflush(stdout);
+  fgets(buf, sizeof(buf), stdin); /* deny echoed line */
   fgets(buf, sizeof(buf), stdin);
   if(strcmp(buf, "OK\r\n")!=0)
     sprog_error("Expected OK, received '%s'\n", buf);