migration: fix COLO broken caused by a previous commit
This commit "migration: Create migration_is_running()" broke
COLO. Becuase there is a process broken by this commit.
colo_process_checkpoint
->colo_do_checkpoint_transaction
->migrate_set_block_enabled
->qmp_migrate_set_capabilities
It can be fixed by make COLO process as an exception,
Maybe we need a better way to fix it.
Cc: Juan Quintela <quintela@redhat.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>