fix incorrect argc < 1 check for no arguments

-requiring arguments should be argc < 2

src/modules/fw_att_control/fw_att_control_main.cpp

@@ -1134,8 +1134,9 @@ FixedwingAttitudeControl::start()
 
 int fw_att_control_main(int argc, char *argv[])
 {
-	if (argc < 1)
+	if (argc < 2) {
 		errx(1, "usage: fw_att_control {start|stop|status}");
+	}
 
 	if (!strcmp(argv[1], "start")) {