fix handling of mavlink mode argument

src/modules/mavlink/mavlink_main.cpp

@@ -1484,9 +1484,11 @@ Mavlink::task_main(int argc, char *argv[])
 
 			} else if (strcmp(myoptarg, "onboard") == 0) {
 				_mode = MAVLINK_MODE_ONBOARD;
-			} else if (strcmp(optarg, "osd") == 0) {
+
+			} else if (strcmp(myoptarg, "osd") == 0) {
 				_mode = MAVLINK_MODE_OSD;
-			} else if (strcmp(optarg, "config") == 0) {
+
+			} else if (strcmp(myoptarg, "config") == 0) {
 				_mode = MAVLINK_MODE_CONFIG;
 			}