Free the session memory correctly

git-svn-id: http://www.varnish-cache.org/svn/trunk@322 d4fa192b-c00b-0410-8231-f00ffab90ce4

bin/varnishd/cache_acceptor.c

@@ -242,7 +242,7 @@ vca_return_session(struct sess *sp)
 	} else {
 		if (sp->http != NULL)
 			http_Delete(sp->http);
-		free(sp);
+		free(sp->mem);
 	}
 }