nvmet: fix the structure member indentation

This is a cleanup patch which fixes the structure member indentation
introduced by the p2p:

commit c6925093 ("nvmet: Optionally use PCI P2P memory").
We don't change any functionality in this patch.

This is needed so that any future members will also follow the uniform
indentation.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Acked-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>