Windows: Fixed I/O bug in the CommOverlappedEventNotifier
Windows: Fixed I/O bug in the CommOverlappedEventNotifier

This bug is a critical regression, which makes it impossible
to read the data as they become available because
CommOverlappedEventNotifier::processCompletionRoutine()
returns false if successful completed, i.e. returns a error flag
instead of inversion it.

Now, processCompletionRoutine() returns true if successful completion.

Change-Id: Id5c103017e10dabfaac6017f26afdf76d14b9e65
Reviewed-by: Sergey Belyashov <8871b4c2d635fca691211507eadbac3d0bc2695a@gmail.com>
Reviewed-by: Laszlo Papp <2164cc32668ec579454611fc5261234262c80421@kde.org>
Reviewed-by: Denis Shienkov <6a9c747bd2ba446682324cf340d3b86f30cf4d55@gmail.com>

kobolabs/qtserialport,kobolabs/qtserialport,RoadWorksSoftware/QtSerialPort-OS2,RoadWorksSoftware/QtSerialPort-OS2