ios: cleaner kill of subprocess of iostoolhandler

try to first terminate (sig TERM) the tool before
killing it (this ensures a cleaner shutdown of the
connection to the device).

Task-number: QTCREATORBUG-10922
Change-Id: Ib39fbd1d35a651cdb51364532bdef5b69cb1347e
Reviewed-by: Fawzi Mohamed <fawzi.mohamed@digia.com>

src/plugins/ios/iostoolhandler.h

@@ -99,6 +99,7 @@ private slots:
     void subprocessError(QProcess::ProcessError error);
     void subprocessFinished(int exitCode, QProcess::ExitStatus exitStatus);
     void subprocessHasData();
+    void killProcess();
 private:
     friend class Ios::Internal::IosToolHandlerPrivate;
     Ios::Internal::IosToolHandlerPrivate *d;