nvme: ignore zone validate errors on subsequent scans

Revalidating nvme zoned namespaces requires IO commands, and there are
controller states that prevent IO. For example, a sanitize in progress
is required to fail all IO, but we don't want to remove a namespace
we've previously added just because the controller is in such a state.
Suppress the error in this case.

Reported-by: Michael Nguyen <michael.nguyen@wdc.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>