ina226/voxlpm: make sure parameter sub is reset

The subscription to parameter updates has to get
copied otherwise the change detection will not get
reset for next time.

src/drivers/power_monitor/ina226/ina226.cpp

@@ -210,9 +210,11 @@ INA226::collect()
 {
 	perf_begin(_sample_perf);
 
-	parameter_update_s param_update;
+	if (_parameter_update_sub.updated()) {
+		// Read from topic to clear updated flag
+		parameter_update_s parameter_update;
+		_parameter_update_sub.copy(&parameter_update);
 
-	if (_parameters_sub.copy(&param_update)) {
 		updateParams();
 	}