Fix error reporting in stream config, report if a stream was not found at all in stream list and return error

src/modules/mavlink/mavlink_main.cpp

@@ -1555,13 +1555,18 @@ Mavlink::configure_stream(const char *stream_name, const float rate)
 				/* delete stream */
 				LL_DELETE(_streams, stream);
 				delete stream;
+				warnx("deleted stream %s", stream->get_name());
 			}
 
 			return OK;
 		}
 	}
 
-	if (interval > 0) {
+	if (interval == 0) {
+		/* stream was not active and is requested to be disabled, do nothing */
+		return OK;
+	}
+
 	/* search for stream with specified name in supported streams list */
 	for (unsigned int i = 0; streams_list[i] != nullptr; i++) {
 
@@ -1572,14 +1577,13 @@ Mavlink::configure_stream(const char *stream_name, const float rate)
 			stream->set_interval(interval);
 			stream->subscribe(this);
 			LL_APPEND(_streams, stream);
+
 			return OK;
 		}
 	}
 
-	} else {
+	/* if we reach here, the stream list does not contain the stream */
-		/* stream not found, nothing to disable */
+	warnx("stream %s not found", stream_name);
-		return OK;
-	}
 
 	return ERROR;
 }