Fix QUIC warnings in preparation for enabling them

gfe-relnote: n/a, compilation-only change
PiperOrigin-RevId: 253893322
Change-Id: I15917a1c5b325922850086277cfad5e3b4da20a4
diff --git a/quic/core/tls_client_handshaker.cc b/quic/core/tls_client_handshaker.cc
index d90b6f5..7024ff8 100644
--- a/quic/core/tls_client_handshaker.cc
+++ b/quic/core/tls_client_handshaker.cc
@@ -23,7 +23,7 @@
 
 void TlsClientHandshaker::ProofVerifierCallbackImpl::Run(
     bool ok,
-    const std::string& error_details,
+    const std::string& /*error_details*/,
     std::unique_ptr<ProofVerifyDetails>* details) {
   if (parent_ == nullptr) {
     return;