Stop using TRUE and FALSE for exit status.

coreutils/sleep.c

@@ -32,7 +32,7 @@ extern int sleep_main(int argc, char **argv)
 
 	if (sleep(atoi(*(++argv))) != 0) {
 		perror("sleep");
-		exit(FALSE);
+		return EXIT_FAILURE;
 	}
-	return(TRUE);
+	return EXIT_SUCCESS;
 }