LLAP: ORC cache NPE without FileID support

   OrcBatchKey stripeKey = hasFileId ? new OrcBatchKey(fileId, -1, 0) : null;
   ...
          if (hasFileId && metadataCache != null) {
            stripeKey.stripeIx = stripeIx;
            stripeMetadata = metadataCache.getStripeMetadata(stripeKey);
          }
...
  public void setStripeMetadata(OrcStripeMetadata m) {
    assert stripes != null;
    stripes[m.getStripeIx()] = m;
  }

Caused by: java.lang.NullPointerException
        at org.apache.hadoop.hive.llap.io.metadata.OrcStripeMetadata.getStripeIx(OrcStripeMetadata.java:106)
        at org.apache.hadoop.hive.llap.io.decode.OrcEncodedDataConsumer.setStripeMetadata(OrcEncodedDataConsumer.java:70)
        at org.apache.hadoop.hive.llap.io.encoded.OrcEncodedDataReader.readStripesMetadata(OrcEncodedDataReader.java:685)
        at org.apache.hadoop.hive.llap.io.encoded.OrcEncodedDataReader.performDataRead(OrcEncodedDataReader.java:283)
        at org.apache.hadoop.hive.llap.io.encoded.OrcEncodedDataReader$4.run(OrcEncodedDataReader.java:215)
        at org.apache.hadoop.hive.llap.io.encoded.OrcEncodedDataReader$4.run(OrcEncodedDataReader.java:212)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.Subject.doAs(Subject.java:415)
        at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1657)
        at org.apache.hadoop.hive.llap.io.encoded.OrcEncodedDataReader.callInternal(OrcEncodedDataReader.java:212)
        at org.apache.hadoop.hive.llap.io.encoded.OrcEncodedDataReader.callInternal(OrcEncodedDataReader.java:93)
        ... 5 more