fix LOCK file deletion to prevent crash on windows

db/db_impl.cc

@@ -1427,7 +1427,7 @@ Status DestroyDB(const std::string& dbname, const Options& options) {
     FileType type;
     for (size_t i = 0; i < filenames.size(); i++) {
       if (ParseFileName(filenames[i], &number, &type) &&
-          filenames[i] != lockname) {  // Lock file will be deleted at end
+          type != kDBLockFile) {  // Lock file will be deleted at end
         Status del = env->DeleteFile(dbname + "/" + filenames[i]);
         if (result.ok() && !del.ok()) {
           result = del;