Make the second argument to routerset_contains_extendinfo const

src/or/or.h

@@ -4504,7 +4504,8 @@ int routerset_needs_geoip(const routerset_t *set);
 int routerset_contains_router(const routerset_t *set, routerinfo_t *ri);
 int routerset_contains_routerstatus(const routerset_t *set,
                                     routerstatus_t *rs);
-int routerset_contains_extendinfo(const routerset_t *set, extend_info_t *ei);
+int routerset_contains_extendinfo(const routerset_t *set,
+                                  const extend_info_t *ei);
 void routerset_get_all_routers(smartlist_t *out, const routerset_t *routerset,
                                int running_only);
 void routersets_get_disjunction(smartlist_t *target, const smartlist_t *source,

src/or/routerlist.c

@@ -5119,7 +5119,7 @@ routerset_contains(const routerset_t *set, const tor_addr_t *addr,
 
 /** Return true iff we can tell that <b>ei</b> is a member of <b>set</b>. */
 int
-routerset_contains_extendinfo(const routerset_t *set, extend_info_t *ei)
+routerset_contains_extendinfo(const routerset_t *set, const extend_info_t *ei)
 {
   return routerset_contains(set,
                             &ei->addr,