The same qt_timeout_value function was copied 5 times in qtbase's code,
so provide a common implementation in QIoDevice that can be used by
everyone.
This commit also corrects the remaining time calculation in
QProcess::waitForBytesWritten and QProcess::waitForFinished by using
this new function.
For QProcess::waitForFinished, if the process started within almost exactly
the timeout time passed to waitForFinished, msecs - stopWatch.elapsed() would
be -1, which is a special value.
Change-Id: I7b76ee6bae695eafdd02e3db03e2ff1e23a7f40c
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
ed0c0070f9