Fixes the log/early return condition in CallbackVisitor::OnMetadataEndForStream.

PiperOrigin-RevId: 540868350

quiche/http2/adapter/callback_visitor.cc

diff --git a/quiche/http2/adapter/callback_visitor.cc b/quiche/http2/adapter/callback_visitor.cc
index 70fff1d..4577ba6 100644
--- a/quiche/http2/adapter/callback_visitor.cc
+++ b/quiche/http2/adapter/callback_visitor.cc
@@ -470,7 +470,7 @@
 }
 
 bool CallbackVisitor::OnMetadataEndForStream(Http2StreamId stream_id) {
-  if (current_frame_.hd.flags != kMetadataEndFlag) {
+  if ((current_frame_.hd.flags & kMetadataEndFlag) == 0) {
     QUICHE_VLOG(1) << "Expected kMetadataEndFlag during call to "
                    << "OnMetadataEndForStream!";
     return true;