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

diff --git a/archival/tar.c b/archival/tar.c
index e634cc6..4323553 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -25,7 +25,7 @@
 
 #include <fnmatch.h>
 #include <getopt.h>
-#include "busybox.h"
+#include "libbb.h"
 #include "unarchive.h"
 
 #if ENABLE_FEATURE_TAR_CREATE