AUTOFS: Fix offline resolution of autofs maps
If talking to the Data Provider failed, we never re-tried looking into
the cache. We should consult the cache on DP failures and return cached
results, if possible.
Resolves:
https://fedorahosted.org/sssd/ticket/3080
Reviewed-by: Pavel Březina <pbrezina@redhat.com>
(cherry picked from commit b9e155da725e711ab306ca8a96e3ba6fbda41a3a)