migration: Add cleanup hook for inwards migration

Add a cleanup hook for incoming migration that gets called
at the end as a way for a transport to allow cleanup.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20210421112834.107651-4-dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
diff --git a/migration/migration.c b/migration/migration.c
index 1885860..393299e 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -280,6 +280,9 @@
         g_array_free(mis->postcopy_remote_fds, TRUE);
         mis->postcopy_remote_fds = NULL;
     }
+    if (mis->transport_cleanup) {
+        mis->transport_cleanup(mis->transport_data);
+    }
 
     qemu_event_reset(&mis->main_thread_load_event);