src: add default value for RSACipherConfig mode field

Using default init of enum is UB Refs: #56693 PR-URL: #56701 Reviewed-By: Juan José Arboleda <soyjuanarbol@gmail.com> Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com> Reviewed-By: James M Snell <jasnell@gmail.com>

Author: wooffie

src/crypto/crypto_rsa.h

@@ -77,7 +77,7 @@ struct RSAKeyExportTraits final {
 using RSAKeyExportJob = KeyExportJob<RSAKeyExportTraits>;
 
 struct RSACipherConfig final : public MemoryRetainer {
- CryptoJobMode mode;
+ CryptoJobMode mode = kCryptoJobAsync;
  ByteSource label;
  int padding = 0;
  const EVP_MD* digest = nullptr;