nvme: freeze the queue over ->lba_shift updates

Ensure that there can't be any I/O in flight went we change the disk
geometry in nvme_update_ns_info, most notable the LBA size by lifting
the queue free from nvme_update_disk_info into the caller

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>