winbindd: let normalize_name_map() call find_domain_from_name_noinit()

winbindd: let normalize_name_map() call find_domain_from_name_noinit()

Let normalize_name_map fetch the domain itself with
find_domain_from_name_noinit().

This removes two calls to find_domain_from_name_noinit() in the default
configuration of "winbind normalize names = no". The domain is only need
in normalize_name_map if "winbind normalize names" is enabled.

Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>