http: fix regression of binary upgrade response body

See: #24958

PR-URL: #25037
Reviewed-By: Myles Borins <myles.borins@gmail.com>

src/node_http_parser.cc

@@ -621,8 +621,6 @@ class Parser : public AsyncWrap {
     size_t nparsed =
       http_parser_execute(&parser_, &settings, data, len);
 
-    enum http_errno err = HTTP_PARSER_ERRNO(&parser_);
-
     Save();
 
     // Unassign the 'buffer_' variable
@@ -637,7 +635,9 @@ class Parser : public AsyncWrap {
     Local<Integer> nparsed_obj = Integer::New(env()->isolate(), nparsed);
     // If there was a parse error in one of the callbacks
     // TODO(bnoordhuis) What if there is an error on EOF?
-    if ((!parser_.upgrade && nparsed != len) || err != HPE_OK) {
+    if (!parser_.upgrade && nparsed != len) {
+      enum http_errno err = HTTP_PARSER_ERRNO(&parser_);
+
       Local<Value> e = Exception::Error(env()->parse_error_string());
       Local<Object> obj = e->ToObject(env()->isolate());
       obj->Set(env()->bytes_parsed_string(), nparsed_obj);