Fix typo: saddr → daddr

nftables.ml

@@ -25,7 +25,7 @@ module Payload = struct
 
     let to_string : type a. a t -> string = function
       | Saddr -> "saddr"
-      | Daddr -> "saddr"
+      | Daddr -> "daddr"
   end
 
   module Ipv6 = struct
@@ -33,7 +33,7 @@ module Payload = struct
 
     let to_string : type a. a t -> string = function
       | Saddr -> "saddr"
-      | Daddr -> "saddr"
+      | Daddr -> "daddr"
   end
 
   type _ t =