Fix a compile error in https://ci.chromium.org/p/chromium/builders/ci/ios-device-xcode-clang/93619

gfe-relnote: n/a (no functional error)
PiperOrigin-RevId: 243188258
Change-Id: I2b06eea96208ba1586338729358836f7f4ce5002

quic/core/quic_types.cc

diff --git a/quic/core/quic_types.cc b/quic/core/quic_types.cc
index bf1a07f..c9e21d6 100644
--- a/quic/core/quic_types.cc
+++ b/quic/core/quic_types.cc
@@ -71,7 +71,7 @@
 
 std::ostream& operator<<(std::ostream& os,
                          const QuicIetfTransportErrorCodes& c) {
-  if (c >= 0xff00) {
+  if (static_cast<uint16_t>(c) >= 0xff00u) {
     os << "Private value: " << c;
     return os;
   }