migration: Avoid two src-downtime-end tracepoints for postcopy

Postcopy can trigger this tracepoint twice, while only the 1st one is
valid.  Avoid triggering the 2nd tracepoint just like what we do with
recording the total downtime.

Signed-off-by: Peter Xu <peterx@redhat.com>
Tested-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Juraj Marcin <jmarcin@redhat.com>
Link: https://lore.kernel.org/r/20250114230746.3268797-5-peterx@redhat.com
Signed-off-by: Fabiano Rosas <farosas@suse.de>
1 file changed