fix the check for libraries having themselves as dependencies

Change-Id: I6dc56228a068fe9158e989afd1c545a3d69848e6
Reviewed-by: Joerg Bornemann <joerg.bornemann@nokia.com>
Reviewed-by: Marius Storm-Olsen <marius.storm-olsen@nokia.com>

mkspecs/features/qt.prf

@@ -168,12 +168,13 @@ for(QTLIB, QT) {
 QT = $$resolve_depends(NEWQT, "QT.")
 # Finally actually add the modules
 for(QTLIB, QT) {
-    isEmpty(QT.$${QTLIB}.name) {
+    QTLIBNAME = $$eval(QT.$${QTLIB}.name)
+    isEmpty(QTLIBNAME) {
         message("Warning: unknown QT module: $$QTLIB")
         next()
     }
 
-    target_qt:isEqual(TARGET, QTLIB) {
+    target_qt:isEqual(TARGET, $$QTLIBNAME) {
         warning($$TARGET cannot have a QT of $$QTLIB)
         next()
     }