IFP: Fix talloc hierarchy for members of struct ifp_list_domains_state
    
    The function talloc_steal was called ifp_list_domains_recv
      *_paths = talloc_steal(mem_ctx, state->paths)
    
    But talloc hierarchy for entries in the list state->paths was not
    correct therefore memory was freed together with the state.
    
    Merges: https://pagure.io/SSSD/sssd/pull-request/4082
    
    Reviewed-by: Alexey Tikhonov <atikhonov@redhat.com>