Fix build error by NULL cast change

[Norikatsu Shigemura]

Hi Yar.

	I fixed build error by recently NULL cast change.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
--- hfs-freebsd-03p1/freebsd/mount_hfs/mount_hfs.c.orig	Sat Aug  9 21:23:47 2003
+++ hfs-freebsd-03p1/freebsd/mount_hfs/mount_hfs.c	Sun Mar  7 09:45:06 2004
@@ -58,7 +58,7 @@
 	MOPT_STDOPTS,
 	MOPT_FORCE,
 	MOPT_UPDATE,
-	{ NULL, NULL, NULL, NULL }
+	{ NULL, 0, 0, 0 }
 };
 
 static gid_t	a_gid __P((char *));
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -