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/extensions.cc b/ssl/extensions.cc
index 3baef6d..47434de 100644
--- a/ssl/extensions.cc
+++ b/ssl/extensions.cc
@@ -2581,7 +2581,7 @@
 
   assert(CBS_len(&copy) == 0);
   *out = std::move(ret);
-  return 1;
+  return true;
 }
 
 static bool ext_supported_groups_parse_clienthello(SSL_HANDSHAKE *hs,