usage.c: remove reference to busybox.h
*: s/include "busybox.h"/include "libbb.h"

diff --git a/networking/hostname.c b/networking/hostname.c
index 3f6a658..50ef7b5 100644
--- a/networking/hostname.c
+++ b/networking/hostname.c
@@ -12,7 +12,7 @@
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */
 
-#include "busybox.h"
+#include "libbb.h"
 
 static void do_sethostname(char *s, int isfile)
 {