nvme-multipath: put module reference when delayed removal work is canceled

nvme-multipath: put module reference when delayed removal work is canceled

The delayed disk removal work is canceled when a NS (re)appears. However,
we do not put the module reference grabbed in nvme_mpath_remove_disk(), so
fix that.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: John Garry <john.g.garry@oracle.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>