generator: run various generators only run on the host, not in initrd

These 5 generators only make sense on the host,not in the initrd, hence
if they end up in the initrd anyway, make them exit quickly.

src/getty-generator/getty-generator.c

@@ -10,6 +10,7 @@
 #include "fd-util.h"
 #include "fileio.h"
 #include "generator.h"
+#include "initrd-util.h"
 #include "log.h"
 #include "mkdir-label.h"
 #include "parse-util.h"
@@ -212,6 +213,11 @@ static int run(const char *dest, const char *dest_early, const char *dest_late)
 
         assert_se(arg_dest = dest);
 
+        if (in_initrd()) {
+                log_debug("Skipping generator, running in the initrd.");
+                return EXIT_SUCCESS;
+        }
+
         r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, 0);
         if (r < 0)
                 log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");