fstab-generator: Do not check deviceless filesystems

There is no need to check those.

src/shared/generator.c

@@ -42,6 +42,11 @@ int generator_write_fsck_deps(
         assert(what);
         assert(where);
 
+        if (fstype_is_deviceless(fstype)) {
+                log_debug("Not checking deviceless filesystem \"%s\".", fstype);
+                return 0;
+        }
+
         if (!is_device_path(what)) {
                 log_warning("Checking was requested for \"%s\", but it is not a device.", what);
                 return 0;