Remove definition of useless reference

It is confusing to have two names to refer to the same thing.

Author: romainbrenguier

src/goto-symex/symex_assign.cpp

@@ -233,29 +233,28 @@ static assignmentt rewrite_with_to_field_symbols(
   assignmentt assignment,
   const namespacet &ns)
 {
-  ssa_exprt &lhs_mod = assignment.lhs;
   if(use_update)
   {
     while(assignment.rhs.id() == ID_update &&
           to_update_expr(assignment.rhs).designator().size() == 1 &&
-          (lhs_mod.type().id() == ID_array ||
-           lhs_mod.type().id() == ID_struct ||
-           lhs_mod.type().id() == ID_struct_tag))
+          (assignment.lhs.type().id() == ID_array ||
+           assignment.lhs.type().id() == ID_struct ||
+           assignment.lhs.type().id() == ID_struct_tag))
     {
       exprt field_sensitive_lhs;
       const update_exprt &update = to_update_expr(assignment.rhs);
       PRECONDITION(update.designator().size() == 1);
       const exprt &designator = update.designator().front();
 
-      if(lhs_mod.type().id() == ID_array)
+      if(assignment.lhs.type().id() == ID_array)
       {
         field_sensitive_lhs =
-          index_exprt(lhs_mod, to_index_designator(designator).index());
+          index_exprt(assignment.lhs, to_index_designator(designator).index());
       }
       else
       {
         field_sensitive_lhs = member_exprt(
-          lhs_mod,
+          assignment.lhs,
           to_member_designator(designator).get_component_name(),
           update.new_value().type());
       }
@@ -266,28 +265,28 @@ static assignmentt rewrite_with_to_field_symbols(
         break;
 
       assignment.rhs = update.new_value();
-      lhs_mod = to_ssa_expr(field_sensitive_lhs);
+      assignment.lhs = to_ssa_expr(field_sensitive_lhs);
     }
   }
   else
   {
     while(assignment.rhs.id() == ID_with &&
           to_with_expr(assignment.rhs).operands().size() == 3 &&
-          (lhs_mod.type().id() == ID_array ||
-           lhs_mod.type().id() == ID_struct ||
-           lhs_mod.type().id() == ID_struct_tag))
+          (assignment.lhs.type().id() == ID_array ||
+           assignment.lhs.type().id() == ID_struct ||
+           assignment.lhs.type().id() == ID_struct_tag))
     {
       exprt field_sensitive_lhs;
       const with_exprt &with_expr = to_with_expr(assignment.rhs);
 
-      if(lhs_mod.type().id() == ID_array)
+      if(assignment.lhs.type().id() == ID_array)
       {
-        field_sensitive_lhs = index_exprt(lhs_mod, with_expr.where());
+        field_sensitive_lhs = index_exprt(assignment.lhs, with_expr.where());
       }
       else
       {
         field_sensitive_lhs = member_exprt(
-          lhs_mod,
+          assignment.lhs,
           with_expr.where().get(ID_component_name),
           with_expr.new_value().type());
       }
@@ -299,7 +298,7 @@ static assignmentt rewrite_with_to_field_symbols(
         break;
 
       assignment.rhs = with_expr.new_value();
-      lhs_mod = to_ssa_expr(field_sensitive_lhs);
+      assignment.lhs = to_ssa_expr(field_sensitive_lhs);
     }
   }
   return assignment;