ptrunc: Only call mds_bmap_write_logrepls() when we have made a change. Otherwise, we will hit no valid replicas assert quickly.
ptrunc: Only call mds_bmap_write_logrepls() when we have made a change.
Otherwise, we will hit no valid replicas assert quickly.

pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable