fixed Curl_freeaddrinfo() to only free addrinfo, and added Curl_freednsinfo()

for freeing single dns cache entries

lib/hostip.c

@@ -88,7 +88,7 @@ static Curl_addrinfo *my_getaddrinfo(struct SessionHandle *data,
 void Curl_global_host_cache_init(void)
 {
   if (!host_cache_initialized) {
-    Curl_hash_init(&hostname_cache, 7, Curl_freeaddrinfo);
+    Curl_hash_init(&hostname_cache, 7, Curl_freednsinfo);
     host_cache_initialized = 1;
   }
 }
@@ -287,17 +287,25 @@ struct Curl_dns_entry *Curl_resolv(struct SessionHandle *data,
 /*
  * This is a wrapper function for freeing name information in a protocol
  * independent way. This takes care of using the appropriate underlaying
- * proper function.
+ * function.
  */
-void Curl_freeaddrinfo(void *freethis)
+void Curl_freeaddrinfo(Curl_addrinfo *p)
+{
+#ifdef ENABLE_IPV6
+  freeaddrinfo(p);
+#else
+  free(p);
+#endif
+}
+
+/*
+ * Free a cache dns entry.
+ */
+void Curl_freednsinfo(void *freethis)
 {
   struct Curl_dns_entry *p = (struct Curl_dns_entry *) freethis;
 
-#ifdef ENABLE_IPV6
-  freeaddrinfo(p->addr);
-#else
-  free(p->addr);
-#endif
+  Curl_freeaddrinfo(p->addr);
 
   free(p);
 }