tst_macdeployqt: fix runVerifyDeployment()

QList rather pointlessly has a startsWith() function, which means this
code compiled. But the code makes no sense: it tests the same
condition over and over again, so I'm assuming that it should be
path.startsWith() and not path_s_.startsWith().

Amends 3f56950862, but that just
imported the code from qttools. I didn't check whether the bug was
present there, already.

Pick-to: 6.6 6.5
Change-Id: I98a4bbfe0400700655a5c2137f7a976a835a8d28
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

tests/auto/tools/macdeployqt/tst_macdeployqt.cpp

@@ -203,7 +203,7 @@ void runVerifyDeployment(const QString &name)
         part = part.trimmed();
         if (part.isEmpty())
             continue;
-        QVERIFY(!parts.startsWith(qtPath));
+        QVERIFY(!part.startsWith(qtPath));
     }
 }