Remove unused special accessors for tallies (#3527)

Author: GuySten

include/openmc/tallies/tally.h

@@ -169,10 +169,8 @@ class Tally {
   // We need to have quick access to some filters.  The following gives indices
   // for various filters that could be in the tally or C_NONE if they are not
   // present.
-  int energy_filter_ {C_NONE};
   int energyout_filter_ {C_NONE};
   int delayedgroup_filter_ {C_NONE};
-  int cell_filter_ {C_NONE};
 
   vector<Trigger> triggers_;
 

src/tallies/tally.cpp

@@ -487,10 +487,6 @@ void Tally::add_filter(Filter* filter)
     energyout_filter_ = filters_.size();
   } else if (filter->type() == FilterType::DELAYED_GROUP) {
     delayedgroup_filter_ = filters_.size();
-  } else if (filter->type() == FilterType::CELL) {
-    cell_filter_ = filters_.size();
-  } else if (filter->type() == FilterType::ENERGY) {
-    energy_filter_ = filters_.size();
   }
   filters_.push_back(filter_idx);
 }