introduce bb_putchar(). saves ~1800 on uclibc (less on glibc).

diff --git a/util-linux/getopt.c b/util-linux/getopt.c
index 94fb457..4767d58 100644
--- a/util-linux/getopt.c
+++ b/util-linux/getopt.c
@@ -195,7 +195,7 @@
 		printf(" --");
 		while (optind < argc)
 			printf(" %s", normalize(argv[optind++]));
-		puts("");
+		bb_putchar('\n');
 	}
 	return exit_code;
 }