failover: Use always atomics for primary_should_be_hidden

Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20201118083748.1328-4-quintela@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
1 file changed