Standardize on the vi editing directives being on the first line.
diff --git a/libbb/xgetcwd.c b/libbb/xgetcwd.c
index 1fcdba1..f6cfb34 100644
--- a/libbb/xgetcwd.c
+++ b/libbb/xgetcwd.c
@@ -1,3 +1,4 @@
+/* vi: set sw=4 ts=4: */
 /*
  * xgetcwd.c -- return current directory with unlimited length
  * Copyright (C) 1992, 1996 Free Software Foundation, Inc.