Destroy dialog properly at unload (rizzo)

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@47309 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

@@ -17022,13 +17022,7 @@ static int unload_module(void)
 	while (p) {
 		pl = p;
 		p = p->next;
-		/* Free associated memory */
-		ast_mutex_destroy(&pl->lock);
-		if (pl->chanvars) {
-			ast_variables_destroy(pl->chanvars);
-			pl->chanvars = NULL;
-		}
-		free(pl);
+		__sip_destroy(pl, TRUE);
 	}
 	iflist = NULL;
 	ast_mutex_unlock(&iflock);