Add usage messages for applets without them.

coreutils/hostid.c

@@ -25,6 +25,9 @@
 
 extern int hostid_main(int argc, char **argv)
 {
+	if (argc > 1 && strcmp(argv[1], "--help") == 0)
+		usage(hostid_usage);
+
 	printf("%lx\n", gethostid());
 	return(TRUE);
 }

coreutils/pwd.c

@@ -30,6 +30,9 @@ extern int pwd_main(int argc, char **argv)
 {
 	char buf[BUFSIZ + 1];
 
+	if (argc > 1 && strcmp(argv[1], "--help") == 0)
+		usage(pwd_usage);
+
 	if (getcwd(buf, sizeof(buf)) == NULL)
 		fatalError("%s\n", strerror(errno));