Bug 28785: Adjust check_cookie_auth calls

Bug 28785: Adjust check_cookie_auth calls

The previous patch makes check_cookie_auth return the session instead of
$sessionID, so we are adjusting the different calls to prevent
confusion.
However they are mainly used to check the authentication status and
don't care about this second variable.

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>