fix reference in "data_set->ticket" of NULL.

In the environment where rsc_ticket is set up, I discovered the phenomenon in which stonithd aborted.

pe_flag_quick_location is set in fencing/main.c.
When pe_flag_quick_location is set, unpack_status() is not carried out.
"data_set->ticket" is made in unpack_status() .
If do_calculations is performed by this flow, "data_set->ticket" will be passed to g_hash_table_lookup() by NULL in unpack_rsc_tickets(). 


```
Jun 07 13:35:36 [5620] vm1 stonith-ng: (     utils.c:1123  )   error: crm_abort:        crm_glib_handler: Forked child 5626 to record non-fatal assert at logging.c:63 : g_hash_table_lookup: assertion `hash_table != NULL' failed
```