Some cleanup of CanSeeOrDetect code.

src/server/game/Entities/GameObject/GameObject.cpp

@@ -854,16 +854,16 @@ bool GameObject::isAlwaysVisibleFor(WorldObject const* seer) const
     return false;
 }
 
-bool GameObject::isVisibleForInState(WorldObject const* seer) const
+bool GameObject::IsInvisibleDueToDespawn() const
 {
-    if (!WorldObject::isVisibleForInState(seer))
-        return false;
+    if (WorldObject::IsInvisibleDueToDespawn())
+        return true;
 
     // Despawned
     if (!isSpawned())
-        return false;
+        return true;
 
-    return true;
+    return false;
 }
 
 void GameObject::Respawn()