Remove obsolete comment from QDataStream test.

The removed comment was introduced before the tests were imported into
the Qt repository in 2006 and seems to relate to code that no longer
exists.

Change-Id: Ic21e46fe0157adf5be9dc62de098517b7b27c310
Reviewed-by: Rohan McGovern <rohan.mcgovern@nokia.com>

tests/auto/corelib/io/qdatastream/tst_qdatastream.cpp

@@ -1463,9 +1463,6 @@ void tst_QDataStream::readQImage(QDataStream *s)
     QVERIFY(d12.depth() == ref.depth());
     QVERIFY(d12.colorCount() == ref.colorCount());
     QVERIFY(d12.hasAlphaChannel() == ref.hasAlphaChannel());
-
-//     ################ Bug : ref and orig has ff in alpha; readback has 0
-//     ### (Was like this in 1.44 as well)
 }
 
 // ************************************