Fix lambda returning `false` instead of `nullptr`

Signed-off-by: Chris Burel <burelc@amazon.com>

Code/Editor/Platform/Windows/Editor/Core/QtEditorApplication_windows.cpp

@@ -135,7 +135,7 @@ namespace Editor
                         }
                         widget = widget->parentWidget();
                     }
-                    return false;
+                    return nullptr;
                 };
                 if (object == toolBarAt(QCursor::pos()))
                 {