[MSPAINT] Follow-up of #5332 (9ff9580)

Simplify the epilogue code of CCanvasWindow::OnSetCursor by using bHandle variable. CORE-18867

base/applications/mspaint/canvas.cpp

@@ -668,7 +668,7 @@ LRESULT CCanvasWindow::OnSetCursor(UINT nMsg, WPARAM wParam, LPARAM lParam, BOOL
     }
 
     if (selectionModel.m_bShow || !setCursorOnSizeBox(CanvasHitTest(pt)))
-        ::SetCursor(::LoadCursor(NULL, IDC_ARROW));
+        bHandled = FALSE;
 
     return 0;
 }