LibWeb: Remove StringBuilder from HTMLToken::m_tag

Author: https://github.com/gunnarbeutner
Commit: 3aa202c432
Pull-request: https://github.com/SerenityOS/serenity/pull/8687
Reviewed-by: https://github.com/alimpfard

Userland/Libraries/LibWeb/HTML/Parser/HTMLDocumentParser.cpp

@@ -1572,8 +1572,7 @@ void HTMLDocumentParser::handle_in_body(HTMLToken& token)
     if (token.is_start_tag() && token.tag_name() == HTML::TagNames::image) {
         // Parse error. Change the token's tag name to HTML::TagNames::img and reprocess it. (Don't ask.)
         log_parse_error();
-        token.m_tag.tag_name.clear();
-        token.m_tag.tag_name.append(HTML::TagNames::img);
+        token.m_tag.tag_name = "img";
         process_using_the_rules_for(m_insertion_mode, token);
         return;
     }