Fix button_to_string when str is empty

Author: pifopi

SerialPrograms/Source/NintendoSwitch/Controllers/NintendoSwitch_ControllerState.cpp

@@ -34,12 +34,12 @@ std::string button_to_string(Button button){
     if (button & BUTTON_LEFT_SR)    str += "Left-SR";
     if (button & BUTTON_RIGHT_SL)   str += "Right-SL";
     if (button & BUTTON_RIGHT_SR)   str += "Right-SR";
+    if (str.empty()) {
+        str = "none";
+    }
     if (str.back() == ' '){
         str.pop_back();
     }
-    if (str.empty()){
-        str = "none";
-    }
     return str;
 }
 std::string dpad_to_string(DpadPosition dpad){