block/replication: drop extra synchronization

After commit f8d59dfb40
    "block/backup: fix fleecing scheme: use serialized writes" fleecing
(specifically reading from backup target, when backup source is in
backing chain of backup target) is safe, because all backup-job writes
to target are serialized. Therefore we don't need additional
synchronization for these reads.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
1 file changed