Fixed qstandardpaths unittest to check before using first()

- Added check to testLocateAll() to check count() before calling
  first().

Change-Id: I04e93c1f913972b26c517f2bbd08760f9898cc7a
Reviewed-by: Kurt Korbatits  <kurt.korbatits@nokia.com>
Reviewed-by: Jason McDonald <jason.mcdonald@nokia.com>
Reviewed-by: Rohan McGovern <rohan.mcgovern@nokia.com>

tests/auto/corelib/io/qstandardpaths/tst_qstandardpaths.cpp

@@ -142,6 +142,7 @@ void tst_qstandardpaths::testLocateAll()
 
     setCustomLocations();
     const QStringList allFiles = QStandardPaths::locateAll(QStandardPaths::ConfigLocation, "qstandardpaths.pro");
+    QVERIFY2(allFiles.count() > 0, "qstandardpaths.pro not found in config locations!");
     QCOMPARE(allFiles.first(), QString(m_thisDir + QString::fromLatin1("/qstandardpaths.pro")));
 #endif
 }