message: Allow copy elision when returning object
diff: @@ -191,7 +191,7 @@ class DCAFitterN
  mat(0, 0) = mat(1, 1) = mTrAux[i].c;
  mat(0, 1) = -mTrAux[i].s;
  mat(1, 0) = mTrAux[i].s;
  - return std::move(mat);
  + return mat;
  }
  MatSym3D getTrackCovMatrix(int i, int cand = 0) const // generate covariance matrix of track position, adding fake X error
  @@ -202,7 +202,7 @@ class DCAFitterN
  mat(1, 1) = trc.getSigmaY2();
  mat(2, 2) = trc.getSigmaZ2();
  mat(2, 1) = trc.getSigmaZY();
  - return std::move(mat);
  + return mat;
  }
  void assign(int) {}
  @@ -604,7 +604,7 @@ ROOT::Math::SMatrix<double, 3, 3, ROOT::Math::MatRepSym<double, 3>> DCAFitterN<N
  for (int i = N; i--;) {
  covm += ROOT::Math::Similarity(mUseAbsDCA ? getTrackRotMatrix(i) : mTrCFVT[mOrder[cand]][i], getTrackCovMatrix(i, cand));
  }
  - return std::move(covm);
  + return covm;
  }
  //___________________________________________________________________
  