Don't init hs intro key as side effect of an assert

changes/bug15211

   o Minor bugfixes:
     - Remove side-effects from tor_assert() calls. This was harmless,
       because we never disable assertions, but it is bad style and
-      unnecessary. Fixes bug 15211; bugfix on 0.2.5.5, 0.2.2.36.
+      unnecessary. Fixes bug 15211; bugfix on 0.2.5.5, 0.2.2.36, and
+      0.2.0.10.
 

src/or/rendservice.c

@@ -3320,7 +3320,8 @@ rend_services_introduce(void)
       intro = tor_malloc_zero(sizeof(rend_intro_point_t));
       intro->extend_info = extend_info_from_node(node, 0);
       intro->intro_key = crypto_pk_new();
-      tor_assert(!crypto_pk_generate_key(intro->intro_key));
+      int fail = crypto_pk_generate_key(intro->intro_key);
+      tor_assert(!fail);
       intro->time_published = -1;
       intro->time_to_expire = -1;
       intro->time_expiring = -1;