DnsIrpCancel(
  IN  PDEVICE_OBJECT DeviceContext,
  IN  PIRP pIrp
  );

Routine Description:

    This routine handles the cancelling a DNS name query Irp that is passed
    down to NBT from Lmhsvc, for the purpose of resolving a name with DNS.
    Nbt will complete this irp each time it has a name to resolve with DNS.

    This routine will get the Resource Lock, and Null the Irp ptr in the
    DnsQueries structure and then return the irp.

Arguments:


Return Value:

    The final status from the operation.