Remove return value from axis functions in API

UI/ControlMappingScreen.cpp

@@ -407,11 +407,11 @@ static bool IgnoreAxisForMapping(int axis) {
 }
 
 
-bool KeyMappingNewKeyDialog::axis(const AxisInput &axis) {
+void KeyMappingNewKeyDialog::axis(const AxisInput &axis) {
 	if (mapped_ || time_now_d() < delayUntil_)
-		return false;
+		return;
 	if (IgnoreAxisForMapping(axis.axisId))
-		return false;
+		return;
 
 	if (axis.value > AXIS_BIND_THRESHOLD) {
 		mapped_ = true;
@@ -428,14 +428,13 @@ bool KeyMappingNewKeyDialog::axis(const AxisInput &axis) {
 		if (callback_)
 			callback_(kdf);
 	}
-	return true;
 }
 
-bool KeyMappingNewMouseKeyDialog::axis(const AxisInput &axis) {
+void KeyMappingNewMouseKeyDialog::axis(const AxisInput &axis) {
 	if (mapped_)
-		return false;
+		return;
 	if (IgnoreAxisForMapping(axis.axisId))
-		return false;
+		return;
 
 	if (axis.value > AXIS_BIND_THRESHOLD) {
 		mapped_ = true;
@@ -452,7 +451,6 @@ bool KeyMappingNewMouseKeyDialog::axis(const AxisInput &axis) {
 		if (callback_)
 			callback_(kdf);
 	}
-	return true;
 }
 
 enum class StickHistoryViewType {
@@ -619,12 +617,12 @@ bool AnalogSetupScreen::key(const KeyInput &key) {
 	return retval;
 }
 
-bool AnalogSetupScreen::axis(const AxisInput &axis) {
+void AnalogSetupScreen::axis(const AxisInput &axis) {
 	// We DON'T call UIScreen::Axis here! Otherwise it'll try to move the UI focus around.
 	// UIScreen::axis(axis);
 
 	// Instead we just send the input directly to the mapper, that we'll visualize.
-	return mapper_.Axis(axis);
+	mapper_.Axis(axis);
 }
 
 void AnalogSetupScreen::CreateViews() {
@@ -778,13 +776,12 @@ bool TouchTestScreen::key(const KeyInput &key) {
 	return true;
 }
 
-bool TouchTestScreen::axis(const AxisInput &axis) {
-
+void TouchTestScreen::axis(const AxisInput &axis) {
 	// This is mainly to catch axis events that would otherwise get translated
 	// into arrow keys, since seeing keyboard arrow key events appear when using
 	// a controller would be confusing for the user.
 	if (IgnoreAxisForMapping(axis.axisId))
-		return false;
+		return;
 
 	const float AXIS_LOG_THRESHOLD = AXIS_BIND_THRESHOLD * 0.5f;
 	if (axis.value > AXIS_LOG_THRESHOLD || axis.value < -AXIS_LOG_THRESHOLD) {
@@ -797,7 +794,6 @@ bool TouchTestScreen::axis(const AxisInput &axis) {
 			lastKeyEvent_->SetText(buf);
 		}
 	}
-	return true;
 }
 
 void TouchTestScreen::render() {