BuildStep: Remove finished() signal and use FutureInterface to report

Remove the finished() signal that is (sometimes) used to report that
a buildstep is done and use the FutureInterface for that purpose
consistently.

Change-Id: Ibe5520b562b91f1a7f4fc73ee898b33b930029ec
Reviewed-by: Tim Jenssen <tim.jenssen@theqtcompany.com>
Reviewed-by: Christian Kandeler <christian.kandeler@theqtcompany.com>

src/plugins/qbsprojectmanager/qbsbuildstep.cpp

@@ -408,8 +408,7 @@ void QbsBuildStep::build()
     m_job = qbsProject()->build(options, m_products, error);
     if (!m_job) {
         emit addOutput(error, ErrorMessageOutput);
-        m_fi->reportResult(false);
-        emit finished();
+        reportRunResult(*m_fi, false);
         return;
     }
 
@@ -430,14 +429,12 @@ void QbsBuildStep::build()
 void QbsBuildStep::finish()
 {
     QTC_ASSERT(m_fi, return);
-    m_fi->reportResult(m_lastWasSuccess);
+    reportRunResult(*m_fi, m_lastWasSuccess);
     m_fi = 0; // do not delete, it is not ours
     if (m_job) {
         m_job->deleteLater();
         m_job = 0;
     }
-
-    emit finished();
 }
 
 QbsProject *QbsBuildStep::qbsProject() const

src/plugins/qbsprojectmanager/qbscleanstep.cpp

@@ -100,8 +100,7 @@ void QbsCleanStep::run(QFutureInterface<bool> &fi)
     m_job = pro->clean(options);
 
     if (!m_job) {
-        m_fi->reportResult(false);
-        emit finished();
+        reportRunResult(*m_fi, false);
         return;
     }
 
@@ -175,12 +174,10 @@ void QbsCleanStep::cleaningDone(bool success)
     }
 
     QTC_ASSERT(m_fi, return);
-    m_fi->reportResult(success);
+    reportRunResult(*m_fi, success);
     m_fi = 0; // do not delete, it is not ours
     m_job->deleteLater();
     m_job = 0;
-
-    emit finished();
 }
 
 void QbsCleanStep::handleTaskStarted(const QString &desciption, int max)

src/plugins/qbsprojectmanager/qbsinstallstep.cpp

@@ -93,8 +93,7 @@ void QbsInstallStep::run(QFutureInterface<bool> &fi)
     m_job = pro->install(m_qbsInstallOptions);
 
     if (!m_job) {
-        m_fi->reportResult(false);
-        emit finished();
+        reportRunResult(*m_fi, false);
         return;
     }
 
@@ -193,12 +192,10 @@ void QbsInstallStep::installDone(bool success)
     }
 
     QTC_ASSERT(m_fi, return);
-    m_fi->reportResult(success);
+    reportRunResult(*m_fi, success);
     m_fi = 0; // do not delete, it is not ours
     m_job->deleteLater();
     m_job = 0;
-
-    emit finished();
 }
 
 void QbsInstallStep::handleTaskStarted(const QString &desciption, int max)