Add qCDebug to tst_QQuickPinchHandler::scaleThreeFingers

When it fails locally, I want to see the actual scale value.

Change-Id: Iecdf1dc2bb9660d3f6d11dea57fb2ca5aafd0068
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

tests/auto/quick/pointerhandlers/qquickpinchhandler/tst_qquickpinchhandler.cpp

@@ -344,6 +344,7 @@ void tst_QQuickPinchHandler::scaleThreeFingers()
 
         QCOMPARE(pinchHandler->active(), true);
         // scale we got was 1.1729088738267854364, but keep some slack
+        qCDebug(lcPointerTests) << "pinch scale" << pinchHandler->scale() << "expected 1.173";
         QVERIFY(withinBounds(1.163, pinchHandler->scale(), 1.183));
         // should not rotate
         QCOMPARE(root->rotation(), 0.);