make use of qtHaveModule()

Change-Id: I14da5455b7dd4681254e1652395df5f5c65746bd
Reviewed-by: Tasuku Suzuki <stasuku@gmail.com>
Reviewed-by: Jonas Rabbe <jonas.rabbe@gmail.com>
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>

src/plugins/wmf/player/player.pri

@@ -24,7 +24,7 @@ SOURCES += \
     $$PWD/mfaudioprobecontrol.cpp \
     $$PWD/mfvideoprobecontrol.cpp
 
-!isEmpty(QT.widgets.name):!simulator {
+qtHaveModule(widgets):!simulator {
     HEADERS += $$PWD/evr9videowindowcontrol.h
     SOURCES += $$PWD/evr9videowindowcontrol.cpp
 }