Debugger: Use QtcProcess::stop instead of stopProcess

Less synchronous in cases where it is not needed.

Change-Id: Ia07e6d293c7f5e6dfb81b06c0ffb6d5d651b88b3
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/debugger/debuggersourcepathmappingwidget.cpp

@@ -453,7 +453,6 @@ static QString findQtInstallPath(const FilePath &qmakePath)
         return QString();
     }
     if (!proc.waitForFinished()) {
-        proc.stopProcess();
         qWarning("%s: Timeout running '%s'.", Q_FUNC_INFO, qPrintable(qmakePath.toString()));
         return QString();
     }