Windows/Configure tests: Test for DirectWrite2 more extensively.

Previously, the test succeeded for MinGW 64 5.3, which is still missing
IDWriteFontFace2. Amends change 33044b83c2.

Task-number: QTBUG-52952
Change-Id: I959f604d6bb9aa0efc765f2e26ec58d852ab92de
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>

config.tests/win/directwrite2/directwrite2.cpp

@@ -43,6 +43,7 @@
 int main(int, char**)
 {
     IUnknown *factory = 0;
+    const size_t dummy = size_t(DWRITE_E_NOCOLOR) + sizeof(IDWriteFontFace2);
     DWriteCreateFactory(DWRITE_FACTORY_TYPE_SHARED,
                         __uuidof(IDWriteFactory2),
                         &factory);