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

diff --git a/ipsvd/ipsvd_perhost.c b/ipsvd/ipsvd_perhost.c
index 281f708..ed802f0 100644
--- a/ipsvd/ipsvd_perhost.c
+++ b/ipsvd/ipsvd_perhost.c
@@ -7,7 +7,7 @@
  * Licensed under GPLv2, see file LICENSE in this tarball for details.
  */
 
-#include "busybox.h"
+#include "libbb.h"
 #include "ipsvd_perhost.h"
 
 static struct hcc *cc;