freebsd_network: Fix debug build.

src/libs/compat/freebsd_network/compat/altq/if_altq.h

@@ -36,6 +36,7 @@ struct ifaltq {
 #define ALTQ_ENQUEUE(ifr, m, foo, error) \
 	do { m_freem(m); error = -1; } while (0)
 #define ALTQ_DEQUEUE(ifr, m)	(m) = NULL
+#define ALTQ_PURGE(ifq)
 
 #define TBR_IS_ENABLED(ifq)		0
 #define tbr_dequeue_ptr(ifq, v)	NULL

src/libs/compat/freebsd_network/compat/sys/sysctl.h

@@ -86,6 +86,14 @@ sysctl_wire_old_buffer(struct sysctl_req *req, size_t len)
 }
 
 
+static inline struct sbuf *
+sbuf_new_for_sysctl(struct sbuf *s, char *buf, int length,
+    struct sysctl_req *req)
+{
+	return NULL;
+}
+
+
 static inline void *
 sysctl_add_oid(struct sysctl_ctx_list *clist, void *parent, int nbr,
 	const char *name, int kind, void *arg1, int arg2,