LSC: Apply clang-tidy's modernize-use-bool-literals to boringssl

The check finds implicit conversions of integer literals to bools:
  bool b1 = 1;
  bool b2 = static_cast<bool>(1);
and transforms them to:
  bool b1 = true;
  bool b2 = true;

Bug: chromium:1290142
Change-Id: I15579e28f544d07b331a230b70a8278e0651150d
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/51085
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
diff --git a/ssl/tls13_both.cc b/ssl/tls13_both.cc
index 226c67b..208c6ff 100644
--- a/ssl/tls13_both.cc
+++ b/ssl/tls13_both.cc
@@ -475,7 +475,7 @@
                        CRYPTO_BUFFER_len(raw)) ||
         !CBB_flush(&extensions)) {
       OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
-      return 0;
+      return false;
     }
     ssl->s3->delegated_credential_used = true;
   }