Use toAccidental instead of using static cast

Author: iwoithe

src/engraving/libmscore/cmd.cpp

@@ -1893,7 +1893,7 @@ void Score::changeAccidental(AccidentalType idx)
     if (selection().isAccentidentalsOnly()) {
         std::vector<EngravingItem*> accidentals = selection().elements(ElementType::ACCIDENTAL);
         for (EngravingItem* accidentalItem : accidentals) {
-            Accidental* accidental = static_cast<Accidental*>(accidentalItem);
+            Accidental* accidental = toAccidental(accidentalItem);
 
             if (accidental->accidentalType() == idx) {
                 changeAccidental(accidental->note(), AccidentalType::NONE);