scd:p15: Handle cards with bad encoded path objects.
* scd/app-p15.c (read_ef_prkdf, read_ef_pukdf) (read_ef_cdf, read_ef_aodf): Allow for a zero length path and correctly skip unsupported auth types.
Backported-from-master: 7a8545c91b09277b0833dc0e5881ba5d1c8dbca3
- Signed-off-by: Werner Koch <wk@gnupg.org>