SUDO: fix tevent style
Rearrage and rename functions in sdap_async_sudo.c to obey
tevent style and improve readability.
Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>
Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>
(cherry picked from commit 24eac34a8c1f0a284cb697e8d5c09ff049181691)