Title: #250: cache_req: Use ternary operator instead of bool+switch
I still don't think it makes anything cleaner, just reduce the
amount of lines.
The main purpose is not reduction of lines. But make it more readable. After the
discussion, it was decided that switch+bool is the less readable form proposed options.
(just you like it :-)
See the full comment at https://github.com/SSSD/sssd/pull/250#issuecomment-297798113