vfs: unbreak builds when MAC is not defined

Sorts out powerpc.QORIQ64 build failure.

Sponsored by:	Rubicon Communications, LLC ("Netgate")

sys/sys/vnode.h

@@ -1002,6 +1002,10 @@ void	vop_mkdir_debugpost(void *a, int rc);
 
 void	vop_rename_fail(struct vop_rename_args *ap);
 
+#ifndef MAC
+#define mac_vnode_check_stat(active_cred, file_cred, vp)	0
+#endif
+
 #define	vop_stat_helper_pre(ap)	({						\
 	struct vop_stat_args *_ap = (ap);					\
 	int _error;								\
@@ -1016,6 +1020,11 @@ void	vop_rename_fail(struct vop_rename_args *ap);
 	_error;									\
 })
 
+
+#ifndef MAC
+#undef mac_vnode_check_stat
+#endif
+
 #define	vop_stat_helper_post(ap, error)	({					\
 	struct vop_stat_args *_ap = (ap);					\
 	int _error = (error);							\