public static String getTableBackupDir(String backupRootDir, String backupId,
    TableName tableName) {
    return backupRootDir + Path.SEPARATOR + backupId + Path.SEPARATOR
      + tableName.getNamespaceAsString() + Path.SEPARATOR + tableName.getQualifierAsString()
      + Path.SEPARATOR;
  }
Given the backup root dir, backup id and the table name, return the backup image location.
Return value look like:
"hdfs://backup.hbase.org:9000/user/biadmin/backup/backup_1396650096738/default/t1_dn/", where
"hdfs://backup.hbase.org:9000/user/biadmin/backup" is a backup root directory
@param backupRootDir backup root directory
@param backupId      backup id
@param tableName     table name
@return backupPath String for the particular table
hbase-backup/src/main/java/org/apache/hadoop/hbase/backup/HBackupFileSystem.java