- fixed check of mbus_sendrecv_request and mbus_recv_frame

- initialized memory in mbus_sendrecv_request
- used defines for special address instead of magic numbers

bin/mbus-tcp-request-data.c

@@ -111,7 +111,7 @@ main(int argc, char **argv)
         }
     }   
 
-    if (mbus_recv_frame(handle, &reply) == -1)
+    if (mbus_recv_frame(handle, &reply) != 0)
     {
         fprintf(stderr, "Failed to receive M-Bus response frame.\n");
         return 1;