nvme: fix comment typos in nvme_create_io_queues

fix comment typos in nvme_create_io_queues() like below.
  _aount_ to _amount_
  _an_    to _can_

Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>