/etc/mtab not exist on OpenBSD

Index: src/solid/devices/backends/fstab/fstabwatcher.cpp
--- src/solid/devices/backends/fstab/fstabwatcher.cpp.orig
+++ src/solid/devices/backends/fstab/fstabwatcher.cpp
@@ -37,6 +37,7 @@ FstabWatcher::FstabWatcher()
         connect(qApp, &QCoreApplication::aboutToQuit, this, &FstabWatcher::orphanFileSystemWatcher);
     }
 
+#ifndef Q_OS_OPENBSD
     m_mtabFile = new QFile(s_mtabFile, this);
     if (m_mtabFile && m_mtabFile->symLinkTarget().startsWith("/proc/") && m_mtabFile->open(QIODevice::ReadOnly)) {
         m_mtabSocketNotifier = new QSocketNotifier(m_mtabFile->handle(), QSocketNotifier::Exception, this);
@@ -44,6 +45,7 @@ FstabWatcher::FstabWatcher()
     } else {
         m_fileSystemWatcher->addPath(s_mtabFile);
     }
+#endif
 
     m_fileSystemWatcher->addPath(s_fstabPath);
     connect(m_fileSystemWatcher, &QFileSystemWatcher::directoryChanged, this, [this](const QString &) {
