fix: formatting build

src/sail_json_backend/json.ml

@@ -617,7 +617,7 @@ let rec string_of_sizeof_field k f =
 
 let is_reserved_field field_name =
   let reserved_prefix = "reserved_bits_" in
-  String.length field_name >= String.length reserved_prefix 
+  String.length field_name >= String.length reserved_prefix
   && String.sub field_name 0 (String.length reserved_prefix) = reserved_prefix
 
 let json_of_field k f =