tst_QSizePolicy: minor cleanup

Fix indention, remove unused functions, slots->Q_SLOTS.

Change-Id: I30ced40dcde2650977424864399b721bbe17013c
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>

tests/auto/widgets/kernel/qsizepolicy/tst_qsizepolicy.cpp

@@ -37,28 +37,15 @@
 
 class tst_QSizePolicy : public QObject
 {
-Q_OBJECT
+    Q_OBJECT
 
-public:
-    tst_QSizePolicy();
-    virtual ~tst_QSizePolicy();
-
-private slots:
+private Q_SLOTS:
     void getSetCheck();
     void dataStream();
     void horizontalStretch();
     void verticalStretch();
 };
 
-tst_QSizePolicy::tst_QSizePolicy()
-{
-}
-
-tst_QSizePolicy::~tst_QSizePolicy()
-{
-}
-
-
 // Testing get/set functions
 void tst_QSizePolicy::getSetCheck()
 {