getncchanges.c: Add ancestor links when the object normally gets sent

getncchanges.c: Add ancestor links when the object normally gets sent

Currently we add links each time we send an object, but we don't
actually send these links until the end of the replication cycle.

In subsequent patches we want the links to be sent in the same chunk as
their source object, ideally in as close to USN order as possible.
Processing ancestors complicates this a bit, as the ancestor will have a
higher USN than what we're currently up to, and so potentially will the
ancestor's links.

This patch moves where the ancestor's links get added to the
getnc_state->la_list. The ancestor's links now get added when the object
would normally get sent based purely on its USN (we update the highwater
mark at this point too).

This should not affect functionality, i.e. because we send all the links
at the end, it should make no difference at what point they get added to
the list.

This duplicates a tiny bit of code, but this will be cleaned up in the
next patch.

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