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

diff --git a/debianutils/mktemp.c b/debianutils/mktemp.c
index ce5bda5..966257a 100644
--- a/debianutils/mktemp.c
+++ b/debianutils/mktemp.c
@@ -9,7 +9,7 @@
  * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
  */
 
-#include "busybox.h"
+#include "libbb.h"
 #include <stdio.h>
 #include <errno.h>
 #include <string.h>