Store a handle for the event handler. This will be used when unloading the

SCTP as a module.

Obtained from:		markj@

sys/netinet/sctp_pcb.h

@@ -259,6 +259,7 @@ struct sctp_base_info {
 	int packet_log_end;
 	uint8_t packet_log_buffer[SCTP_PACKET_LOG_SIZE];
 #endif
+	eventhandler_tag eh_tag;
 };
 
 /*-

sys/netinet/sctp_usrreq.c

@@ -90,8 +90,8 @@ sctp_init(void)
 	SCTP_BASE_VAR(packet_log_end) = 0;
 	memset(&SCTP_BASE_VAR(packet_log_buffer), 0, SCTP_PACKET_LOG_SIZE);
 #endif
-	EVENTHANDLER_REGISTER(rt_addrmsg, sctp_addr_change_event_handler,
-	    NULL, EVENTHANDLER_PRI_FIRST);
+	SCTP_BASE_VAR(eh_tag) = EVENTHANDLER_REGISTER(rt_addrmsg,
+	    sctp_addr_change_event_handler, NULL, EVENTHANDLER_PRI_FIRST);
 }
 
 #ifdef VIMAGE