[Eva] Utils: slightly improves the precision of [zone_of_expr].

src/plugins/eva/utils/eva_utils.ml

@@ -300,8 +300,7 @@ let rec zone_of_expr find_loc expr =
    then its contents themselves are read *)
 and zone_of_lval find_loc lval =
   let ploc = find_loc lval in
-  let loc = Precise_locs.imprecise_location ploc in
-  let zone = Locations.(enumerate_valid_bits Read loc) in
+  let zone = Precise_locs.enumerate_valid_bits Read ploc in
   Locations.Zone.join zone
     (indirect_zone_of_lval find_loc lval)