[TIDYING] Replacing function "set_difference" with the equivalent sta…

…ndard library function.

Signed-off-by: Jonathan Knowles <jonathan.knowles@eu.citrix.com>

ocaml/xapi/xapi_pif.ml

@@ -16,6 +16,7 @@ open D
 
 module L = Debug.Debugger (struct let name="license" end)
 
+open Listext
 open Stringext
 
 let bridge_naming_convention (device: string) =
@@ -185,8 +186,6 @@ let find_or_create_network (bridge: string) (device: string) ~__context =
 			~bridge ~other_config:[] ~blobs:[] ~tags:[] in
 		net_ref
 
-let set_difference a b = List.filter (fun x -> not(List.mem x b)) a
-
 type tables = {
 	mac_to_pif_table: (string * API.ref_PIF) list;
 	mac_to_phy_table: (string * string) list;
@@ -427,7 +426,7 @@ let scan ~__context ~host =
 					~t ~__context ~host ~mAC:mac ~mTU ~vLAN:(-1L)
 					~vLAN_master_of:Ref.null ~device () in
 			())
-		(set_difference physical_macs existing_macs);
+		(List.set_difference physical_macs existing_macs);
 
 	(* Make sure the right PIF(s) are marked as management PIFs *)
 	update_management_flags ~__context ~host
@@ -448,7 +447,7 @@ let scan_bios ~__context ~host =
 				introduce_internal
 					~t ~__context ~host ~mAC:mac ~mTU ~vLAN:(-1L)
 					~vLAN_master_of:Ref.null ~device:device' ())
-			(set_difference physical_macs existing_macs) in
+			(List.set_difference physical_macs existing_macs) in
 	new_pifs
 
 (* DEPRECATED! Rewritten to use VLAN.create. *)

ocaml/xapi/xapi_pif.mli

@@ -126,9 +126,6 @@ val read_bridges_from_inventory : unit -> string list
 val find_or_create_network :
   string -> string -> __context:Context.t -> [ `network ] Ref.t
 
-(** Compute the set difference a - b *)
-val set_difference : 'a list -> 'a list -> 'a list
-
 (** Convenient lookup tables for scanning etc *)
 type tables = {
   mac_to_pif_table : (string * API.ref_PIF) list;	(** MAC address to PIF reference (all PIFs) *)