ConsoleProcess: Uniform the common interface of QtcProcess

This is a preliminary step before merging ConsoleProcess
into QtcProcess.

Remove processError() signal, use errorOccurred() instead.

Change-Id: If11064944228c82a9099fffdba942c4276690085
Reviewed-by: hjk <hjk@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

src/plugins/debugger/terminal.h

@@ -86,7 +86,7 @@ private:
     void stop() final;
 
     void stubStarted();
-    void stubError(const QString &msg);
+    void stubError();
 
     Utils::ConsoleProcess m_stubProc;
     std::function<ProjectExplorer::Runnable()> m_stubRunnable;