Unnecessary setting of mrgTypeNeighbours in getInterMergeCandidates() and checking condition in getInterMMVDMergeCandidates()

[wangyang.cs]

The unnecessary setting of mrgTypeNeighbours in PU::getInterMergeCandidates() should be removed.

void PU::getInterMergeCandidates()
{
  if ( mrgCtx.interDirNeighbours[uiArrayAddr] == 1 && pu.cs->slice->getRefPic(REF_PIC_LIST_0, mrgCtx.mvFieldNeighbours[uiArrayAddr << 1].refIdx)->getPOC() == pu.cs->slice->getPOC())
    {
      mrgCtx.mrgTypeNeighbours[uiArrayAddr] = MRG_TYPE_IBC;
    }
}

Since the merge types for all merge candidates for MMVD are MRG_TYPE_DEFAULT_N, the unnecessary checking condition in PU::getInterMMVDMergeCandidates() should be removed.

void PU::getInterMMVDMergeCandidates()
{
  for (k = 0; k < maxNumMergeCand; k++)
  {
    if (mrgCtx.mrgTypeNeighbours[k] == MRG_TYPE_DEFAULT_N)
    {
      refIdxList0 = mrgCtx.mvFieldNeighbours[(k << 1)].refIdx;       
      refIdxList1 = mrgCtx.mvFieldNeighbours[(k << 1) + 1].refIdx;
      ...
    }
  }
}

[wangyang.cs]

It may cause problems for multilayer coding when the reference picture and the current picture has the same POC.

[wangyang.cs]

A MR ​https://vcgit.hhi.fraunhofer.de/jvet/VVCSoftware_VTM/-/merge_requests/1889 is submitted.