Windows/ICU: Compile fix.

Change-Id: I95c281b0e577a89e4d92dd16fd039ab9e53036f5
Reviewed-by: Konstantin Ritt <ritt.ks@gmail.com>
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>

src/corelib/tools/qcollator.cpp

@@ -565,7 +565,7 @@ QStringList QCollator::indexCharacters() const
         if (U_FAILURE(status)) {
             d->indexCharacters = englishIndexCharacters();
         } else {
-            QString chars = QString::fromUtf16(val, len);
+            QString chars(reinterpret_cast<const QChar *>(val), len);
             chars.remove('[');
             chars.remove(']');
             chars.remove('{');