[SYS-7551] Don't use options file (facebook#322)

Summary:
We seem to have lost
https://github.com/rockset/rocksdb-cloud/pull/130/files when we pulled
latest RocksDB.

Test Plan:
Internal test

Reviewers:

db/db_impl/db_impl.cc

@@ -6010,6 +6010,9 @@ Status DestroyDB(const std::string& dbname, const Options& options,
 
 Status DBImpl::WriteOptionsFile(bool db_mutex_already_held) {
   options_mutex_.AssertHeld();
+  if (!immutable_db_options_.use_options_file) {
+    return Status::OK();
+  }
 
   if (db_mutex_already_held) {
     mutex_.AssertHeld();

db/version_edit.cc

@@ -962,6 +962,8 @@ std::string VersionEdit::DebugString(bool hex_key) const {
     }
     r.append(" oldest_ancester_time:");
     AppendNumberTo(&r, f.oldest_ancester_time);
+    r.append(" largest_seqno:");
+    AppendNumberTo(&r, f.fd.largest_seqno);
     r.append(" file_creation_time:");
     AppendNumberTo(&r, f.file_creation_time);
     r.append(" epoch_number:");