Notifications: do not send notification about successful writing twice

We already handle case where the helper successfully writes the image before it exits
so there is no reason to handle it again and send the same notification

app/linuxdrivemanager.cpp

@@ -354,10 +354,7 @@ void LinuxDrive::onFinished(int exitCode, QProcess::ExitStatus status) {
             m_image->setStatus(ReleaseVariant::FAILED);
         }
     }
-    else {
-        Notifications::notify(tr("Finished!"), tr("Writing %1 was successful").arg(m_image->fullName()));
-        m_image->setStatus(ReleaseVariant::FINISHED);
-    }
+
     if (m_process) {
         m_process->deleteLater();
         m_process = nullptr;