put `const' back, now that the .m4 test works

diff --git a/lib/dirfd.c b/lib/dirfd.c
index 77ada78..e234063 100644 (file)
--- a/lib/dirfd.c
+++ b/lib/dirfd.c
@@ -24,7 +24,7 @@
 #include "dirfd.h"
 
 int
-dirfd (DIR *dir_p)
+dirfd (DIR const *dir_p)
 {
   return DIR_TO_FD;
 }