tst_qcomobject: Reduce size of Qt-namespace

It is including the full test, which we normally don't do, and
additionally included the main and the moc-include.

Change-Id: I651d71848f070a9d0fd62e56ebd204f4c1ae232c
Reviewed-by: Jøger Hansegård <joger.hansegard@qt.io>

tests/auto/corelib/platform/windows/qcomobject/tst_qcomobject.cpp

@@ -69,6 +69,7 @@ struct QComObjectTraits<IDirect>
 };
 
 } // namespace QtPrivate
+QT_END_NAMESPACE
 
 class tst_QComObject : public QObject
 {
@@ -263,6 +264,4 @@ void tst_QComObject::Release_decrementsReferenceCountByOne()
 QTEST_MAIN(tst_QComObject)
 #  include "tst_qcomobject.moc"
 
-QT_END_NAMESPACE
-
 #endif // Q_OS_WIN