Made function reference into a link in docs

util.mli

@@ -138,10 +138,10 @@ File "foo.cvc", line 10, characters 8-11:
         ^^^ v} *)
 val prerr_loc_msg : Types.location -> string -> unit
 
-(** Print an error message for a node. Calls prerr_loc_msg. *)
+(** Print an error message for a node. Calls {!prerr_loc_msg}. *)
 val node_error : Types.node -> string -> unit
 
-(** Print a warning message for a node. Calls prerr_loc_msg. *)
+(** Print a warning message for a node. Calls {!prerr_loc_msg}. *)
 val node_warning : Types.node -> string -> unit
 
 (** {2 String utilities} *)