MakePartialMdl(
  IN  tCONNECTELE      *pConnEle,
  IN  PIRP             pIrp,
  IN  ULONG            ToCopy
  );

Routine Description:

    This routine is called to build a partial Mdl that accounts for ToCopy
    bytes of data being copied to the start of the Client's Mdl.

Arguments:

    pConnEle    - ptr to the connection element

Return Value:

    NTSTATUS - Status of event indication