CMakeBuildStep: Don't use stdError

Emit addOutput() signal directly. This will add a newline after
the message. Use OutputFormat::ErrorMessage instead of
OutputFormat::Stderr.

Change-Id: Id5e95dd00dca5e57b67c583a1b11071bf4101880
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Cristian Adam <cristian.adam@qt.io>

src/plugins/cmakeprojectmanager/cmakebuildstep.cpp

@@ -352,7 +352,8 @@ void CMakeBuildStep::handleProjectWasParsed(bool success)
     } else if (success) {
         runImpl();
     } else {
-        AbstractProcessStep::stdError(Tr::tr("Project did not parse successfully, cannot build."));
+        emit addOutput(Tr::tr("Project did not parse successfully, cannot build."),
+                       OutputFormat::ErrorMessage);
         emit finished(false);
     }
 }