compare doubles to doubles

Summary:
Should resolve undefined reference to `bool QTest::qCompare<double, int>
error on 5.9

Test Plan:
Still compiles/passes
Not actually tested on 5.9

Reviewers: #kwin, #plasma

Subscribers: kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D13526

autotests/integration/scene_qpainter_shadow_test.cpp

@@ -764,10 +764,10 @@ void SceneQPainterShadowTest::testShadowTextureReconstruction()
     // Check whether we've got right shadow.
     auto shadowIface = client->surface()->shadow();
     QVERIFY(!shadowIface.isNull());
-    QCOMPARE(shadowIface->offset().left(),   128);
-    QCOMPARE(shadowIface->offset().top(),    128);
-    QCOMPARE(shadowIface->offset().right(),  128);
-    QCOMPARE(shadowIface->offset().bottom(), 128);
+    QCOMPARE(shadowIface->offset().left(),   128.0);
+    QCOMPARE(shadowIface->offset().top(),    128.0);
+    QCOMPARE(shadowIface->offset().right(),  128.0);
+    QCOMPARE(shadowIface->offset().bottom(), 128.0);
 
     // Get SceneQPainterShadow's texture.
     QVERIFY(client->effectWindow());