migration/multifd: Change multifd_load_cleanup() signature and usage

Since it's introduction in commit f986c3d256 ("migration: Create multifd
migration threads"), multifd_load_cleanup() never returned any value
different than 0, neither set up any error on errp.

Even though, on process_incoming_migration_bh() an if clause uses it's
return value to decide on setting autostart = false, which will never
happen.

In order to simplify the codebase, change multifd_load_cleanup() signature
to 'void multifd_load_cleanup(void)', and for every usage remove error
handling or decision made based on return value != 0.

Fixes: b5eea99ec2 ("migration: Add yank feature")
Reported-by: Li Xiaohui <xiaohli@redhat.com>
Signed-off-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

migration/migration.c

@@ -559,13 +559,7 @@ static void process_incoming_migration_bh(void *opaque)
      */
     qemu_announce_self(&mis->announce_timer, migrate_announce_params());
 
-    if (multifd_load_cleanup(&local_err) != 0) {
-        error_report_err(local_err);
-        autostart = false;
-    }
-    /* If global state section was not received or we are in running
-       state, we need to obey autostart. Any other state is set with
-       runstate_set. */
+    multifd_load_cleanup();
 
     dirty_bitmap_mig_before_vm_start();
 
@@ -665,9 +659,9 @@ fail:
     migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
                       MIGRATION_STATUS_FAILED);
     qemu_fclose(mis->from_src_file);
-    if (multifd_load_cleanup(&local_err) != 0) {
-        error_report_err(local_err);
-    }
+
+    multifd_load_cleanup();
+
     exit(EXIT_FAILURE);
 }
 

migration/multifd.c

@@ -1013,12 +1013,12 @@ static void multifd_recv_terminate_threads(Error *err)
     }
 }
 
-int multifd_load_cleanup(Error **errp)
+void multifd_load_cleanup(void)
 {
     int i;
 
     if (!migrate_use_multifd()) {
-        return 0;
+        return;
     }
     multifd_recv_terminate_threads(NULL);
     for (i = 0; i < migrate_multifd_channels(); i++) {
@@ -1058,8 +1058,6 @@ int multifd_load_cleanup(Error **errp)
     multifd_recv_state->params = NULL;
     g_free(multifd_recv_state);
     multifd_recv_state = NULL;
-
-    return 0;
 }
 
 void multifd_recv_sync_main(void)

migration/multifd.h

@@ -16,7 +16,7 @@
 int multifd_save_setup(Error **errp);
 void multifd_save_cleanup(void);
 int multifd_load_setup(Error **errp);
-int multifd_load_cleanup(Error **errp);
+void multifd_load_cleanup(void);
 bool multifd_recv_all_channels_created(void);
 void multifd_recv_new_channel(QIOChannel *ioc, Error **errp);
 void multifd_recv_sync_main(void);