Utils: Fix crash in fsengine test

Change-Id: I6a28dfc907d34f1a6e20bc92f5cc506b308f1c0b
Reviewed-by: Eike Ziller <eike.ziller@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

src/libs/utils/filepath.cpp

@@ -828,6 +828,10 @@ DeviceFileAccess *FilePath::fileAccess() const
 
 bool FilePath::hasFileAccess() const
 {
+    // Happens during startup and in tst_fsengine
+    if (!s_deviceHooks.fileAccess)
+        return false;
+
     DeviceFileAccess *access = s_deviceHooks.fileAccess(*this);
     return access;
 }