The resync seek that follows a disc-initiated jump must not reposition
the VM. On BD the jump is handled out-of-band by reopening the slave
demuxer on the packet-read path, and the VM already sits at the jump
destination. Repositioning it with the (stale) seek target time would
hop to the wrong place. Adopting the discontinuity counter here would
leave the old slave demuxer parsing the new playlist's data with the
wrong codec context. Flush our side only, and keep the counter stale so
the read path still performs the reopen.