fix incorrect argc < 1 check for no arguments

-requiring arguments should be argc < 2

src/modules/sensors/sensors.cpp

@@ -2252,7 +2252,7 @@ Sensors::start()
 
 int sensors_main(int argc, char *argv[])
 {
-	if (argc < 1) {
+	if (argc < 2) {
 		errx(1, "usage: sensors {start|stop|status}");
 	}