libnet: Reset debug counters after replicating critical objects

libnet: Reset debug counters after replicating critical objects

Reset the debug counters once we have finished replicating a given
partition. This helps if we replicate the same partition immediately
afterward with different options.

This helps the DC join debug look less weird. Because it replicates the
critical objects first, and then the base partition, previously it
always ended up overcounting, e.g.

Partition[DC=addom,DC=samba,DC=example,DC=com] objects[314/218]
  linked_values[48/24]

Signed-off-by: Tim Beale <timbeale@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>