LArROD: Make numerically more robust.

In loops like

      for (size_t i=0;i<len;++i) {
        Am1+=(samp_no_ped[i])*ofca[i];
      }

change to compute the intermediate results in double precision. Otherwise, the results may change depending on whether FMA instructions are used.

Fixes test failure seen on aarch64. However, this may cause tiny changes in the calorimeter cell reconstruction.