Add a helper to cleanup the transport listener.

When do it, we should also null-ify the cleanup hook and the data, then it's
even safe to call it multiple times.

Move the socket_address_list cleanup altogether, because that's a mirror of the
listener channels and only for the purpose of query-migrate.  Hence when
someone wants to cleanup the listener transport, it should also want to cleanup
the socket list too, always.

No functional change intended.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
---
 migration/migration.c | 22 ++++++++++++++--------
 migration/migration.h |  1 +
 2 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/migration/migration.c b/migration/migration.c
index b2e6446457..6bb321cdd3 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -279,6 +279,19 @@ MigrationIncomingState *migration_incoming_get_current(void)
     return current_incoming;
 }
 
+void migration_incoming_transport_cleanup(MigrationIncomingState *mis)
+{
+    if (mis->socket_address_list) {
+        qapi_free_SocketAddressList(mis->socket_address_list);
+        mis->socket_address_list = NULL;
+    }
+
+    if (mis->transport_cleanup) {
+        mis->transport_cleanup(mis->transport_data);
+        mis->transport_data = mis->transport_cleanup = NULL;
+    }
+}
+
 void migration_incoming_state_destroy(void)
 {
     struct MigrationIncomingState *mis = migration_incoming_get_current();
@@ -299,10 +312,8 @@ void migration_incoming_state_destroy(void)
         g_array_free(mis->postcopy_remote_fds, TRUE);
         mis->postcopy_remote_fds = NULL;
     }
-    if (mis->transport_cleanup) {
-        mis->transport_cleanup(mis->transport_data);
-    }
 
+    migration_incoming_transport_cleanup(mis);
     qemu_event_reset(&mis->main_thread_load_event);
 
     if (mis->page_requested) {
@@ -310,11 +321,6 @@ void migration_incoming_state_destroy(void)
         mis->page_requested = NULL;
     }
 
-    if (mis->socket_address_list) {
-        qapi_free_SocketAddressList(mis->socket_address_list);
-        mis->socket_address_list = NULL;
-    }
-
     yank_unregister_instance(MIGRATION_YANK_INSTANCE);
 }
 
diff --git a/migration/migration.h b/migration/migration.h
index d677a750c9..f17ccc657c 100644
--- a/migration/migration.h
+++ b/migration/migration.h
@@ -166,6 +166,7 @@ struct MigrationIncomingState {
 
 MigrationIncomingState *migration_incoming_get_current(void);
 void migration_incoming_state_destroy(void);
+void migration_incoming_transport_cleanup(MigrationIncomingState *mis);
 /*
  * Functions to work with blocktime context
  */
-- 
2.32.0