simplify loop over modules

the earlier done topological sort already removes duplicates and only
works with lower-cased names anyway, so we can remove the overhead here.

Change-Id: I44fc39af9e94662717e1c8cfb0ddb87d2f597935
Reviewed-by: Joerg Bornemann <joerg.bornemann@nokia.com>

mkspecs/features/qt.prf

@@ -131,7 +131,7 @@ QT = $$sort_depends(QT, "QT.")
 QT_DEPENDS=
 
 unset(using_privates)
-for(QTLIB, $$list($$lower($$unique(QT)))) {
+for(QTLIB, QT) {
     # Figure out if we're wanting to use the private headers of a module
     contains(QTLIB, .*-private) {
         QTLIB ~= s/-private//