private MTable getMTable(String catName, String db, String table) {
    AttachedMTableInfo nmtbl = getMTable(catName, db, table, false);
    return nmtbl.mtbl;
  }
Convert PrivilegeGrantInfo from privMap to MTablePrivilege, and add all of
them to the toPersistPrivObjs. These privilege objects will be persisted as
part of createTable.
standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/ObjectStore.java