Remove a block of code which dates back to commit 8a2ab2b920, when
dns_zone_asyncload() did not yet check DNS_ZONEFLG_LOADPENDING.
Currently, no race in accessing DNS_ZONEFLG_LOADPENDING is possible any
more, because:
- dns_zone_asyncload() is still the only function which may queue
zone_asyncload(),
- dns_zone_asyncload() accesses DNS_ZONEFLG_LOADPENDING under a lock
(and potentially queues an event under the same lock),
- DNS_ZONEFLG_LOADPENDING is not cleared until the load actually
completes.
Thus, the rechecking code can be safely removed from zone_asyncload().
Note that this also brings zone_asyncload() to a state in which the
completion callback is always invoked. This is required to prevent
leaking memory in case something goes wrong in zone_asyncload() and a
zone table the zone belongs to is indefinitely left with a positive
reference count.
840c9348bf