fixup! CP-51493: Add set_cgroup

Author: GabrielBuica

ocaml/libs/tgroup/tgroup.mli

@@ -70,9 +70,7 @@ module Cgroup : sig
 
   val set_cgroup : Group.Creator.t -> unit
   (** [set_cgroup c] sets the current xapi thread in a cgroup based on the
-      creator [c].
-      
-      @raises Cgroups_not_initialized if [init dir] has not been called. *)
+      creator [c].*)
 end
 
 val of_req_originator : string option -> unit