maint: use new emit_try_help in place of equivalent fprintf

Run this command:
  perl -0777 -pi -e \
   's/fprintf \(stderr, _\("Try `%s --help.*\n.*;/emit_try_help ();/m'\
     src/*.c

src/printf.c

@@ -82,8 +82,7 @@ void
 usage (int status)
 {
   if (status != EXIT_SUCCESS)
-    fprintf (stderr, _("Try `%s --help' for more information.\n"),
-             program_name);
+    emit_try_help ();
   else
     {
       printf (_("\