nfsv4.1: resulting notification bitmap should match requests length

Motivation:
Though bitmap can have an arbitrary length, the linux 5.10 client expects
device notification bitmap to be size of one (1).

Modification:
Update OperationGETDEVICEINFO to initialize resulting notification bitmap
with the length that matches requested notification bitmap.

Result:
Linux 5.10 client processes the result of getdeviceinfo operation as expected.

Target: 0.22, master
Acked-by: Paul Millar
Acked-by: Albert Rossi
1 job for master in 1 minute and 10 seconds (queued for 25 seconds)
Status Name Job ID Coverage
  Build
passed build #7106

00:01:10