block/qcow2-bitmap: fix free_bitmap_clusters

This assert may fail, because bitmap_table is not initialized. Just
drop it, as it's obvious, that bitmap_table_load sets bitmap_table
parameter only when returning zero.

Reported-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20180608101225.2575-1-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
1 file changed