nvme: fixup scan failure for non-ANA multipath controllers

Commit 62baf70c caused the ANA log page to be re-read, even on
controllers that do not support ANA.  While this should generally
harmless, some controllers hang on the unsupported log page and
never finish probing.

Fixes: 62baf70c ("nvme: re-read ANA log page after ns scan completes")
Signed-off-by: Hannes Reinecke <hare@kernel.org>
Tested-by: Srikanth Aithal <sraithal@amd.com>
[hch: more detailed commit message]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>