src: add check for Bignum in GroupOrderSize

I think it's missed, cause in this file we have example of checking result of BignumPointer::new Refs: #56692 PR-URL: #56702 Fixes: #56692 Reviewed-By: James M Snell <jasnell@gmail.com>

Author: wooffie

src/crypto/crypto_ec.cc

@@ -918,6 +918,7 @@ size_t GroupOrderSize(const EVPKeyPointer& key) {
  const EC_KEY* ec = key;
  CHECK_NOT_NULL(ec);
  auto order = BignumPointer::New();
+ CHECK(order);
  CHECK(EC_GROUP_get_order(ECKeyPointer::GetGroup(ec), order.get(), nullptr));
  return order.byteLength();
 }