Add more details to error message

Change-Id: I250f41eac1f876d19b297a0b5966ffe30c5298d3
Reviewed-on: http://review.couchbase.org/9875
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>

src/instance.c

@@ -540,8 +540,11 @@ static void libchouchbase_instance_connect_handler(evutil_socket_t sock,
         }
 
         if (instance->curr_ai == NULL) {
+            char errinfo[1024];
+            snprintf(errinfo, sizeof(errinfo), "Failed to look up \"%s:%s\"",
+                     instance->host, instance->port);
             libcouchbase_error_handler(instance, LIBCOUCHBASE_NETWORK_ERROR,
-                                       "Failed to lookup host!\n");
+                                       errinfo);
             return ;
         }