Perform first inspector text update immediately

Provides better and more consistent initial state for the inspector.

osu.Game/Rulesets/Edit/HitObjectInspector.cs

@@ -46,6 +46,7 @@ protected override void LoadComplete()
             EditorBeatmap.SelectedHitObjects.CollectionChanged += (_, _) => updateInspectorText();
             EditorBeatmap.TransactionBegan += updateInspectorText;
             EditorBeatmap.TransactionEnded += updateInspectorText;
+            updateInspectorText();
         }
 
         private ScheduledDelegate? rollingTextUpdate;