nvme: re-read ANA log page after ns scan completes

When scanning for new namespaces we might have missed an ANA AEN.

The NVMe base spec (NVMe Base Specification v2.1, Figure 151 'Asynchonous
Event Information - Notice': Asymmetric Namespace Access Change) states:

  A controller shall not send this even if an Attached Namespace
  Attribute Changed asynchronous event [...] is sent for the same event.

so we need to re-read the ANA log page after we rescanned the namespace
list to update the ANA states of the new namespaces.

Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>